For many Americans nowadays, it’s hard to conceive of life without computers. But such a life is within the living memory of America’s seniors. The first electronic computer was publicly demonstrated on Valentine’s Day 1946 at the University of Pennsylvania. Inventors J. Presper Eckert and John Mauchly developed the computer to help calculate the proper ballistic trajectory for artillery shells. It filled a large room with 18,000 vacuum tubes and the resulting heat. Eckert and Mauchly went on to develop the first commercial computer — UNIVAC I — used to process the 1950 Census. Today, the U.S. is one of the most computerized nations in the world. Over 85 percent of America’s 117 million households have a computer, and nearly 75 percent access the Internet. Profile America is in its19th year as a public service of the U.S. Census Bureau.