This page presents the history of Pennsylvania passenger car license plates from the first year of issue, through the last annual plate.
Latest noteworthy updates to this page
From 1906 until 1979, Pennsylvania license plates displayed the year of issuance. However, plates dated from 1941 until 1979 actually expired on March 31 of the following year. Plates dated from 1941 through 1957 also showed the exact expiration date in addition to the year of issue. Pennsylvania passenger car plates were issued in pairs from 1906 to 1943, and from 1947 to 1951. From 1944 to 1946, and since 1952, single plates have been issued.
My "Pictorial History" pages are intended to be a supplement to the information found in the ALPCA Archives. I am providing additional details and additional photos not found in the archives, and clarifying information when appropriate. When the ALPCA archives cover a subject in great detail, I do not repeat that detail here. I sincerely hope that you find this information useful.
If you find an error or have additional information, or can provide a plate or a photo of a plate that I'm missing, please send me an e-mail. There's a link to my e-mail address at the bottom of every page. Please note that all plates shown that are credited to another person are plates that I am still seeking for my own collection.
Pennsylvania state-issued license plates were first issued in 1906. The 1906 through 1909 license plates actually indicated that the driver, not the vehicle, was licensed. Serial numbers were all-numeric and started from 1, but even in the first year, registrations exceeded 10,000.
By law, the serial number digits were 5 inches tall; the plates themselves were 6 1/2 inches high. The plate width varied based on the number of digits. These plates bore the state abbreviation Penna and the four-digit year, as did all Pennsylvania passenger car plates through 1957. These elements were placed along the top of the plate, except for plates with one- or two-digit serials, on which they were placed to the right of the serial number.
These plates were made of iron coated with porcelain. The porcelain coating preserved the iron well and retained its shine, and many very nice examples may still be found. The down side is that porcelain chips very easily, and therefore it can be relatively difficult to find an unchipped plate from this era.
|1906 –||white on blue||1908 –||black on yellow|
|1907 –||white on red||1909 –||black on white|
Close-up of the keystone tab
Plates from 1910-1915 were again made using a porcelain coating over iron. Beginning in 1910, Pennsylvania license plates were assigned to the vehicle rather than the driver. To drive home that point, a metal tab in the shape of a keystone was rivited to the license plate; stamped on the tab were the words Not Transferable at the top and Makers Number [sic] at the bottom. Engraved on the center of the tab was the "maker's number", or the vehicle serial number, better known today as the VIN number. The keystone tab was attached to the left side of the plate; above it was the Penna state abbreviation, and below it was the four-digit year. Plate height was reduced to 6 inches since the state name and year were no longer above the serial number; since then, Pennsylvania plates have more or less remained 6 inches high through the present day. Plate widths continued to vary based on the number of digits in the all-numeric serial number.
During some years, there were minor variations in design. All plates from this time period were basically flat, except for some 1911 plates, which had beveled edges. The 1911 plate shown above is one of these. In 1914, registrations exceeded 100,000 for the first time, and so serial numbers could be up to 6 digits from that year through 1929. There are also apparently two versions of the 1915 plate; one with and one without a period after the state abbreviation "Penna".
1914 plate probably used on a
A fairly large number of 1914 plates in the 20000 and 30000 series, and a smaller number of 1915 plates in the 20000 series, have a large blank space to the left of the state abbreviation, keystone, and year. These were apparently intended to be used as truck plates, which was a new plate type introduced in 1914. It seems that especially in 1914, the state significantly overestimated the number of truck plates needed, and they apparently issued the extras to cars. Actual truck plates would have a vertical metal band with one or more stars on it affixed to the blank space on the plate. Lots of these 1914 plates, always in the mid- to upper-20000 series and the entire 30000 series, and a smaller number of 1915 plates in the upper-20000 series, have no metal band, but do have an attached keystone with a VIN number, indicating that they were issued to a specific vehicle.
A small number of plates have the word "SPECIAL" stamped onto the keystone tab instead of the vehicle manufacturer's VIN number. It's not known exactly why this was done; possibly these keystones were used for vehicles that were either homemade or cobbled together from several vehicles, and so did not have a VIN.
|1910 –||white on blue||1912 –||white on woodgrain brown||1914 –||white on black|
|1911 –||black on yellow||1913 –||white on green||1915 –||white on medium blue|
The 1916 to 1919 plates were similar visually to the 1910-1915 plates, but actually had several important differences. The most obvious difference was the switch in materials from porcelain to the more familiar embossed steel. Also, the maker's number (VIN number) was enscribed directly onto the embossed keystone, rather than onto a tab riveted to the plate. However, the riveted-on keystones were still occassionally used, in cases where the owner transferred the plate from one vehicle to another during the registration year. For some unknown reason, the keystone, state abbreviation, and year were moved from the left side of the plate to the right side for 1919. Six-digit plates were 16 inches in length, while plates with fewer digits were shorter. These steel plates have not held up as well over time as did their porcelain predecessors.
A small number of plates have the word "SPECIAL" enscribed onto the embossed keystone, or stamped onto the keystone tab, instead of the vehicle manufacturer's VIN number. It's not known exactly why this was done; possibly this designation was used for vehicles that were either homemade or cobbled together from several vehicles, and so did not have a VIN.
A visitor to this page named Deni Corbett wrote to me and shared an interesting family story related to Pennsylvania's switch from porcelain to embossed license plates during the mid-1910s. Her grandfather, John Wilbur Powell, was a printer in western Pennsylvania at the time. Deni says that Mr. Powell invented the license plate embossing machine that the state first used to produce the 1916 plates. Of course, most of the 1916 plates would have been manufactured in 1915. Anyway, while making preparations for the state to use his machine, Mr. Powell found himself spending much time away from home, at such places as the state capital in Harrisburg, and the state prison in which the plate manufacturing facilty was being established. During one of these absences in 1914, Mr. Powell missed the birth of a daughter. This daughter, Deni's mother, was still going strong at age 92 when Deni wrote me in August 2006.
Deni is looking for more information about her grandfather and his involvement with Pennsylvania license plates. If anyone can supply any additional details, please contact me and I will forward the information to her.
|1916 –||black on orange||1918 –||white on black|
|1917 –||white on brown||1919 –||red on black|
Beginning with the 1920 issue, Pennsylvania ceased engraving the vehicle serial number onto the plate itself or onto a tab riveted to the plate. Thus, the large keystone emblem on which the vehicle serial number was engraved was no longer needed. The state abbreviation Penna and the four-digit year were relocated to the bottom of the plate 1920-1926, and then the top of the plate 1927-1929. The state abbreviation and year were flanked by two small embossed keystones beginning in 1921. Beginning in 1923, plate colors were no longer random, but alternated between dark yellow on blue-black in odd years and blue-black on dark yellow in even years. Blue-black is an extremely dark blue that is nearly black; however, it seems that as these plates have aged, the blue-black paint has changed (faded?) so that it may now appear to be black.
Passenger car plates continued to be all-numeric through 1923. During 1924, passenger registrations reached one million for the first time, and the 6-digit numeric serial format was exhausted. Rather than go to a 7-digit plate, an alpha prefix was introduced. Only letters A through F were used for passenger car plates during these years; other letters were used for various types of non-passenger plates. However, letter E was used for passenger plates only beginning in 1928; prior to that it was used for tractor plates. Presumably, if the growth in vehicle registrations was steady, about one new letter per year would have been introduced. Like the all-numeric plates, letter prefix plates could also have from one to six characters.
During the years 1920-1929, a dash separator was used between the third and fourth digits counting from the right, for serials with six characters, and also in some years but not others for serials with four or five characters. Alpha characters were the same size as numeric digits in 1924 and 1925; from 1926 to the present day, serial letters have been noticeably smaller than numbers. 1924 and some 1925 plates with alpha prefixes had the dash immediately following the letter and preceding the numbers; late-issue 1925 and all 1926-1929 passenger car plates with alpha prefixes had dashes in the same position as all-numeric plates. Plate length again varied by number of serial digits. Six-character plates continued to be 16 inches long through mid-year 1923, and then 15 inches long from late-issue 1923 plates through 1929. This size change on the 1923 plates occurred in the upper 800-000 series. My five-character 1925 and 1929 plates are 13 inches long, and my four-character 1927 plate is 10 inches long.
|1920 –||white on blue-black||1923 –||yellow on blue-black (also subsequent odd years through 1935)|
|1921 –||black on yellow||1924 –||blue-black on yellow (also subsequent even years through 1936)|
|1922 –||brown on cream|
For 1930, Pennsylvania introduced a new passenger serial format scheme that had a maximum of five characters. No doubt, part of their motivation for doing so was to avoid the cost of making extra-long plates capable of carrying six or even seven characters. The serial numbers could be anywhere from one to five characters, and could be all-numeric, or contain one letter or two adjacent letters. One- and two-character plates could be all-alphabetic. The dash separator was no longer used. Unlike the 1924-1929 plates, the location of the letter(s) in the serial number now varied, and the letter(s) could be in the entire range of A-Z. However, letters I, O, Q, T, W, and X were not used on passenger car plates; some of these were used on other types of plates. Also, note that 1930 and 1931 plates with serial format 000xx are truck plates. This format would reappear in about the late 1940s on passenger car plates.
Other than the serial format, these plates were similar to those of preceding years. Either at the top or the bottom of the plate were the four-digit year and the abbreviation Penna, flanked by two small embossed keystones. The year could appear before or after the state abbreviation. Colors continued to alternate between blue-black on dark yellow in even years, and dark yellow on blue-black in odd years. Plates were issued in pairs. Five-character plates meausred 12 inches long by 6 inches high, while plates with four or fewer characters were 10 inches long by 6 inches high. In either cases, the bolt holes were 8 1/2 inches apart horizontally on center, and 4 3/4 inches apart vertically on center.
There were two different versions of the 1933 plate, both of which are shown above. The more common version has the state abbreviation followed by the year. The second version had the year first, then the state abbreviation. The serial dies were changed for 1934; this is evident by comparing the number "5" on the 1933 vs. 1934 plates shown. The new dies were used through mid-year 1956. The 1936 plate differed from other years in that its embossed border was not painted in the contrasting color.
Beginning with the 1931 plates, motorists were able to request specific plate numbers for their vehicles. These weren't quite the same same thing as today's vanity plates, as the available letter and number combinations were limited to standard passenger car plate numbers with five or fewer characters through 1964. A person might request a plate number that consisted of his initials and birthday, for example. There was no ready way to tell if a particular plate number was a reserverd number or a random, sequentially-issued number. However, plate numbers with fewer than four characters and/or with two letters were especially popular as reserved numbers.
The 1937 Pennsylvania plate was a significant departure visually from previous years. It featured an embossed border in the shape of the state map. Serial formats continued unchanged from 1936, with a maximum of five characters. The year and state name abbreviation were standardized in their location, now always appearing at the top of the plate, with the four-digit year followed by the abbreviation Penna. The blue color was also lightened from the extremely dark blue-black to a shade that was still dark but more obviously blue. The dark blue and dark yellow colors were used continuously from 1937 to 2000.
The keystones that had flanked the year and state abbeviation in previous years were initially dropped on 1937 passenger car plates, but then inexplicably made a brief reappearance on late-issue 1937 plates. Known 1937 plates with keystones all have serial format 0xx00, with the first letter either "M" or "N". For 1938, the flanking keystones were again removed, and this time were gone for good.
It seems that while four- and five-character plates were issued to the masses, plates with three or fewer characters became rather scarce. I've never heard of any one- or two- character passenger car plates during these years, and have only recently (2009) become aware of a small number of three-character plates issued in the 1950s. The anecdotal evidence seems to indicate that three-character plates could only be had by special request, and even then, I suspect that political connections were probably necessary. Apparently, at least some four-character combinations were also obtained this same way.
Close-up of the 1943 renewal tab
From 1937 to 1942, the plate colors continued to alternate between dark yellow on dark blue in odd years, and dark blue on dark yellow in even years, and plates were issued in pairs. However, in 1943, new plates were not issued due to the metal shortage caused by World War II. Instead, motorists were issued pairs of black on red metal tabs to validate their 1942 plates for 1943. According to the accompanying instructions, these tabs were to be attached to the 1942 plate at the top left bolt hole; in practice, however, it seems that motorists attached the tabs at either upper bolt hole as they saw fit. The tab featured an embossed keystone outline with the year "43" inside, and a still smaller "3-31-44" expiration date and an engraved serial number. New plates were issued for 1944, and from then until 1958, the plate colors were dark yellow on dark blue in even years, and dark blue on dark yellow in odd years. Single plates were issued in 1944 through 1946, pairs were issued 1947 through 1951, and singles again beginning in 1952 through the present day.
There were minor changes to the appearance of these plates throughout the 21 years in which they were used. The actual expiration date of the plate was added to the top border of the plate beginning with the 1941 issue. I'm assuming that this change coincided with a shifting of the expiration date from December 31 to March 31. The expiraition date was always the March 31 of the year following the issue year that continued to be displayed prominently on the main part of the plate. Thus, the dated 1941 plate also indicated on the top border Exp. 3-31-42. The length of the plate was changed every few years, and with it the shape of the eastern border of the state map outline. "Shorty" plates continued to be issued for serial numbers with only four characters until about the mid-1940s; starting then, all plates in a given year were the same length regardless of the number of serial digits. However, 1952 plates were made in two different lengths. Early issues were longer, the same size as 1951 plates; late issues were shorter, the same size as 1953 plates. Both versions are shown above.
In the late 1940s, serial format 000xx was first used for passenger car plates; previoulsy this format had only been used for truck plates in 1930 and 1931. Then, in about 1951, all of the four- and five-character serial formats that were either all-numeric, had one serial letter, or had two adjacent letters were completely exhausted. Then, five-character plates with two non-adjacent letters were introduced. However, these formats, with the first letters A, B, and R through Z, were already being used for non-passenger plates, and so passenger car plates with split formats only used C through P as the first letter. Split-letter passenger formats were first issued in format x000x, then x00x0, then finally x0x00. These split-letter formats were exhausted in late 1956, and very late 1956 plates were then issued in format xx000, and also apparently in format xx00, using letters T and W in the second position. Until then, those letters had been avoided on passenger car plates. For 1957, all split-letter formats were discontinued on passenger car plates; instead, all-numeric six-digit serial numbers were reintroduced; this format had not been used since 1929. There was no space or separator on six-digit 1957 plates.
Late in 1956, in the middle of the x0x00 serial format, the dies used for the serial number were changed so that the thickness of the character strokes was reduced. During 1957, a second set of serial dies with narrower characters was introduced, allowing for a maximum of six characters rather than five. 1957 plates with four or five characters used the wide, thin-stroke dies introduced in late 1956, while six-character 1957 plates used the narrower thin-stroke dies. From 1958 through 1970, the narrower dies were used for all plates regardless of the number of serial characters.
The distance between the bolt holes was constant through 1955 at 8 1/2 inches horizontally and 4 3/4 inches vertically. In the mid-1950s, states voluntarily agreed to standardize their license plate dimensions and bolt hole positions. Pennsylvania adopted this standard beginning with their 1956 plates. The standard calls for the plates to measure 12 inches by 6 inches, with 7 inches between the bolt holes horizontally, and 4 3/4 inches between the bolt holes vertically. This standard size and bolt hole placement continues to be used today across most of the Western Hemisphere.
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Thanks to those who have directly contributed to the information on this page: Deni Corbett, Dale Low, Bill Geibe, John McDevitt, Peter Cohen, Ned Flynn, Norman Taylor, Ralph Talotta, and Nick Smith.
Low, Geibe, and Taylor photographs are presumed to be copyrighted by Dale Low, Bill Geibe, and Norman Taylor respectively, and are used with permission. Likewise, the 1908 plate photgraph is presumed to be copyrighted, and is used with permission of its owner.
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