In 1974, a McDonald's manager based in Dallas, Texas set out to renovate an Oklahoma City restaurant. The first McDonald's drive-thru was supposed to be an elaborate affair, but in the end, it was neither intricate nor did it belong to the state of Oklahoma.

The first McDonald's drive-thru that opened in January 1975 was a small, attendant-sized hole that restaurant manager David Rich cut into the wall of his McDonald's franchise in Sierra Vista, Arizona. The sliding window wasn’t glamorous, probably because Rich designed it to attract soldiers instead of civilians.

Back then, soldiers couldn’t enter restaurants in their uniforms, which is why Rich’s plan worked. Soldiers would queue up to be served at McDonald's first ever drive-thru. When the much-anticipated Oklahoma City drive-thru opened that spring, sales at that McDonald's restaurant rose by 40% in just two months.