While license plate style and number are potentially an incredibly valuable feature for researching an image, readable license plates in RPPCs are a surprisingly uncommon phenomenon. In the early period of the postcard era (c.1905 – 1915), automobiles were not yet ubiquitous helping to account for their scarcity in photographs. Around this time, however, autos went from an infrequent sight to abundant in numbers, a process that occurred with amazing rapidity. Even so, autos with readable license plates never became a common occurance on RPPCs.
Fortunately for those interested in such things, license plate styles evolved in a regular and well documented way. Joe Wasielewski has an excellent website on historical Connecticut license plates. Wikipedia also has a good webpage with a significant amount of material adapted from the former. Early Connecticut license plates for private motorists began with the letter C which was followed by up to five numbers. The plates were in various solid colors, changing annually, with the registration number in an alternate color. From 1914 – 1918, the plates included the state abbreviation CONN down the the left side of the plate, the year down the right side, and the registration numbers were no longer prefixed with C. From 1919 – 1931, the state abreviation CONN and the year were on the bottom of the plate under the registration number. In 1932, the longer style plate was replaced with a shorter rectangular 6″ x 9″ plate. Initially, the state abbreviation and year continued at the bottom of the plate but, beginning in 1937, moved back to the side of the plate. This placement lasted until 1948 when the state abbreviation was changed to CT and moved back to the bottom of the plate. In 1956, the abbreviation was changed back to CONN. Introduction of the modern standard rectangular 6″ x 12″ plate occured in 1957 and was acompanied by a change to the white lettering on blue background color scheme long familiar to many Connecticut residents. This new color scheme, in contrast with the regularly evolving coloring schemes of the pre-1957 era, stayed constant for years.
Registration numbers for Connecticut motorists were regularly published by the state. While locating these publications either in libraries or privately held can be challenging, many have been scanned and placed on the internet providing wide access to researchers. Given a year and license plate number, one can easily look up in whose name a car was registered. Motor vehicle registration lists for the years 1903 through 1914 are listed below. Further registration lists through 1920 are available through the link below. These registration lists all derive from the Connecticut State Library.
Joe Wasielewski’s website. www.ctplates.info
Wikipedia page. link
Connecticut motor vehicle registrations, 1903-1920. link