Green card

The idea began with the Alien Registration Act of 1940: every registered alien was mailed a white Form AR-3 receipt card. After World War II, new arrivals registered at the port, and lawful permanent residents got Form I-151, the Alien Registration Receipt Card, printed on green paper. In the early 1950s, after the Internal Security Act, new INS regulations let AR-3 holders who could prove lawful admission exchange it for an I-151.

Its color gave it its name, and the name stuck even after the card turned pale blue in 1964 and dark blue in 1965. INS issued 19 designs to fight counterfeits before replacing the I-151 with Form I-551 in 1977.