Poster, "The Women's Liberation Movement," 1970

George Washington carried folding beds, tents, eating utensils, and other equipment to use while encamped on the field with his troops during the Revolutionary War. Washington likely used this bed when he traveled from his Newburgh, New York, headquarters in July 1783 -- as the war was winding down -- to tour upstate New York and the military installations located there.

In 1948, the McDonald brothers transformed their Southern California drive-in restaurant with their radical new "Speedee Service System"--assembly-line production of a limited menu at drastically reduced prices. Richard McDonald created this sign design in 1952. In 1955, milkshake machine salesman Ray Kroc franchised the McDonald's concept--prompting numerous imitators and ultimately turning America into a "fast food nation."

In the 1970s, women's rights activists rallied in support of the proposed Equal Rights Amendment (ERA), which would guarantee women equal rights with men as part of the United States Constitution. The ERA, first put forward in 1923, finally passed both houses of Congress in 1972 -- but it was not ratified in enough state legislatures for approval.