On May 11, 1971 Mariano Martinez, a restaurant owner in Dallas, had a great idea. Martinez converted a soft-serve ice cream machine into a frozen margarita machine.

Frozen Margarita Machine (PHOTO BY RICHARD W. STRAUSS)

While the blender had been around since the 1930s, the margarita machine made life easier for bartenders, according to the museum. It’s worth contemplating — before or after your margaritas — whether the light bulb, the telephone or the margarita machine have brought more joy to your life.