Trailer plates were first issued in 1915.
1915-1938T1 - T99999
The 1921-1925 plates pictured here were issued in the standard size (about 15 inches wide)
but were cut down by the original owners to fit the trailer that they were mounted on.
1939-1960T/A 000; T/A 0000
T/A 00A; T/A 000A
1943Dated 43 - no tab
Starting in 1945, the prefix letters on trailer plates started with T/K (?). (Previously, T/A was the first prefix.)
Also, the numbering expanded to 4 digits by 1946, and large-size trailer plates were issued.
The 1952 series went from T/L 1000 to T/Z 9999, then from T/L 100A upward.
These plates were valid with tabs through 1960.
These are listed in order of issuance.
In 1956 or 1957, trailers started getting the 6x12 sized plates. The changeover occurred between T/M 681C and T/M 643J.
In late 1959 or early 1960, the plates went from steel to aluminum, the N.J. moved back to the bottom,
and the new dies were used. This happened between T/R 926E and T/R 204K.