The Patent Act of 1793 and 1836 barred enslaved Africans from obtaining patents because they were not considered citizens.
In 1861, Jefferson Davis, president of the Confederate States of America, enacted a patent law that allowed enslaved Africans to receive patent protection for their inventions, according to Bloomberg.com.
In 1870, the U.S. government passed a patent law giving all American men, including Blacks, the rights to their inventions.
Benjamin Montgomery was born into slavery in 1819 in Loudon County, Virginia.
Montgomery obtained employment at a general store owned by his master Joseph Davis. He would eventually take over the entire purchasing and shipping operations of the store. During those days, merchandise was shipped by boat on the rivers connecting counties and states. However a timely shipment was not guaranteed since the depths of water in different spots throughout the river made navigation difficult.
In an effort to expedite the shipment of merchandise, Montgomery invented a propeller that could cut into the water at different angles, thus allowing the boat to navigate more easily though shallow water.
Montgomery attempted to patent his invention after regaining his freedom, but was rejected again.