Isaac Craft was an African American engineer and inventor, born around 1810, who in 1869 patented a "balanced valve" for a steam engine.
Craft could design a complex valve, but he had never been taught to read or write. So Craft got an attorney to help him with the patent application, which Craft signed with his mark.
This is Isaac Craft’s only known patent, but it was not his only patentable idea. In 1867, two years prior to this patent, we see this news item in the Cincinnati Commercial:
“Finally, we have an inventor in the person of Isaac Craft, who invented a piece of machinery, now extensively used in connection with the steam engine, but which goes by the name of the man who stole the idea from him, taking advantage of Craft’s poverty.”
Census records and city directories show that Isaac Craft was originally from Tennessee, was married to a woman named Lucy, and worked in downtown Cincinnati at the corner of Eggleston and Broadway. Isaac Craft died of asthma on 24 June 1875, at around the age of sixty-five.
Craft's death certificate says that he is buried in Union Baptist Cemetery. Cemetery records show that Isaac Craft owned a family plot at Section B, Lot 51 – a prominent location near the road – but there is no marker for him at this location.