According to the Mystic Stamp Company, the 1968 Thomas Jefferson green 1-cent stamp is worth roughly 20 cents in mint condition and 15 cents in worn condition as of 2014. It is still extremely common and not highly sought after by collectors because to its young age.
The stamp is part of the “Prominent Americans Series,” which ran from 1968 to 1981 and honoured 25 people who made significant contributions to American history. The face value of the Jefferson stamp is the lowest of the series. The series began with a 4-cent stamp of Abraham Lincoln in 1965 and ended with a 5-cent stamp of George Washington in 1981.