Final answer:
The Homestead Act allowed U.S. citizens to claim land if they lived on it and/or farmed it for five years.
Step-by-step explanation:
The act that allowed U.S. citizens to claim a section of land if they lived on it and/or farmed it for five years is the Homestead Act. Under this act, any head of household, or individual over the age of twenty-one, could receive 160 acres of land for a nominal fee. They were required to improve the land within five years by clearing acres, building houses or barns, and maintaining livestock.