After the war, as members of various gangs of outlaws, Jesse and Frank robbed banks, stagecoaches, and trains across the Midwest, gaining national fame and often popular sympathy despite the brutality of their crimes. The James brothers were most active as members of their own gang from about 1866 until 1876, when as a result of their attempted robbery of a bank in Northfield, Minnesota, several members of the gang were captured or killed. They continued in crime for several years afterward, recruiting new members, but came under increasing pressure from law enforcement seeking to bring them to justice. On April 3, 1882, Jesse James was shot and killed by Robert Ford, a new recruit to the gang who hoped to collect a reward on James's head and a promised amnesty for his previous crimes. Already a celebrity in life, James became a legendary figure of the Wild West after his death.
https://en.wikipedia.org/wiki/Jesse_James#Further_reading