February 18, 2007
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Profile America for the 18th day of Black History Month. Few people knew more about heating and air conditioning than David Crosthwait. When not many African-Americans did so, he had earned bachelor and masters degrees in engineering by 1920, and spent his entire working life improving the systems that make life easier for all of us today. He held 39 patents for heating systems, vacuum pumps, refrigeration methods and temperature regulating devices. In 1975 the year before he died Crosthwait was awarded an honorary doctoral degree from his old alma mater, Purdue University. The U.S. grants more than 164,000 patents each year, about half of them to U.S. citizens and corporations. This special Profile America for Black History Month is a public service of the U.S. Census Bureau.