Alexandria, Egypt - About 2000 years ago  Heron of Alexandria a.k.a. Hero was a great mathematician and mechanics inventor that was born around 10 AD.  Some historians say earlier and some say later.  Although it seems no one can agree exactly when Heron was born, the scientific community recognizes the important contributions this man has made to civilization or could have made if discovered sooner.

Heron describes not one, but two different automatic door applications.  The first application used heat from a fire lit by the city's temple priest.  After, a few hours  atmospheric pressure built up in a brass vessel causing it to pump water into adjacent holding containers.  These holding containers acted as weights, which through a series of ropes and pulleys would open the temple's doors, at just about the time people were to arrive for prayer.  Heron used a similar application to open the gates to the city.

Horton Automatics developed and sold the first automatic sliding door in America in 1960. The company co-founders Dee Horton and Lew Hewitt invented the sliding automatic door in 1954. Their automatic doors used a mat actuator.

"The idea came to Lew Hewitt and Dee Horton to build an automatic sliding door back in the mid-1950's,  when they saw that existing swing doors had difficulty operating  in Corpus Christi's winds. So the two men went to work inventing an automatic sliding door that would circumvent the problem of high winds and their damaging effect.  Horton Automatics Inc. was formed in 1960, placing the first commercial automatic sliding door on the market and literally establishing a brand-new industry."