African Americans Influential in Technology In the 1920s and 1930s David Crosthwait invented a vacuum pump, a boiler, and a thermostat control. These inventions were all for more effective heating systems for larger buildings. Crosthwait lived during segregation and the Jim Crow era, where it was relatively rare for an African American to achieve notability in sciences. His parents and teachers were supportive of his interest in science and inventing at an early age. He went to an all-black school in Kansas City, Kansas. While attending he earned a full academic scholarship to Purdue University . He got his bachelor's degree at Purdue University in 1913 and a Masters in 1920. After his studies, from 1925 to 1930, he became a Research Engineer, Director of Research Laboratories for C.A. Dunham Company. He created many different heating systems, refrigeration methods, temperature regulating devices, and vacuum pumps. He holds 39 U.S. patents and 80 i...