"We didn't march home in victory. We did what we were supposed to do, which is stop this aggressive force called communism," said McEachin, a Silver Star recipient.
Edward Chang, director of the Young Oak Kim Center for Korean American Studies at the University of California, Riverside, said U.S. intervention gave South Korea the opportunity to become one of the world's major economies.
"Most Americans simply are not aware of what is happening in Korea and how it happened," he said.
More than 36,000 U.S. service members were killed in the conflict, and millions overall.
The government did not talk to troops at the time about how pivotal the war was in stopping communism. After the victory in World War II, the Korean conflict seemed to almost provoke shame for Americans, McEachin said.
The American public also felt no connection to the fighting in a faraway Asian country unlike during World War II when airwaves filled with patriotic fight songs, he said.
McEachin not only returned to indifference but discrimination as an African American soldier.
After the plane carrying returning troops was delayed in Montana by snow, he was turned away from a hotel where his fellow white soldiers were staying.
Korea was the first conflict in which all U.S. military units were integrated racially. Clark said the float's veterans reflect that important historical milestone.
Clark said it's important Americans learn the war's history because the problem is ever present, a point driven home by the heavily mined armistice line, a 4-kilometer-wide (2.5-mile-wide) demilitarized strip stretching 220 kilometers (135 miles) across the peninsula.
"This serves as a reminder that there is unfinished business on the Korean peninsula," he said.