"JSA/JSA, Part 5 of 5"
*Together with the modern Justice Society, the entire JSA of 1951 comes out of retirement to protect President Truman from Per Degaton, who plans to kill him and have the death blamed on the heroes. With help from a time-travelling Starwoman (Stargirl's young half-sister), the heroes are able to rally their forces and defeat Degaton, though when Rip Hunter arrives to take the modern heroes home, he tells them that the 1950s heroes will not remember this adventure. On returning, Stargirl is delighted to see that her family is still alive, that their actions in the past prevented their assassination.* Source: DCGuide.com