Who is the only U.S. President to invent and patent something?

Question

What term was used to describe the pattern where, from 1840 to 1960, each American President who had won election in a year ending in zero died in office?

Answer 1

Thanks for the query.

Abraham Lincoln (February 12, 1809 – April 15, 1865), 16th President of USA patented an invention to lift boats over shoals and obstruction in a river. It is the only US patent ever registered to a President of the United States.

Source: https://en.wikipedia.org/wiki/Abraham_Lincoln%27s_patent