A: Steam engines were among the most popular products shown at expos during the late 1800s due to their wide use of textiles and materials from industrial sectors.

The steam engine was introduced at the first London Expo, where visitors gawked over a 700-horsepower steam locomotive.

This later gave rise to the Corliss steam engine, which was presented at the 1876 expo in Philadelphia. In 1893 at the Columbia Exposition, a collection of 43 steam engines capable of delivering up to 20,000 horsepower provided energy to 127 generators that were used to supply electricity to the expo's pavilions.