Look at the handheld tablet or smartphone you carry in your pocket or purse. It seems difficult to believe it is far more powerful than the Univac-I computer that weighed 13 tons, had 5,200 vacuum tubes, and took up a whole garage. Only 46 Univac-I computers were ever built but it revolutionized the world.
Grace Hopper, born in New York in 1906, was an associate professor of mathematics at Vassar when WWII broke out. Volunteering for the US Navy Reserve, she was assigned to the Bureau of Ships Computation Project, where she worked on the Harvard Mark I project (a calculating machine used in the war effort), from 1944–9, co-authoring several papers.
In 1949, she moved to the Eckert-Mauchly Computer Corporation (later acquired by Remington Rand, and later still by Unisys), and joined the UNIVAC team. UNIVAC, which first ran in 1951, was the second commercially available computer in the US, and the first designed for business and admin rather than for scientific use. That meant that it was intended to execute many simple calculations rapidly, rather than performing fewer complex calculations. Punch-card calculating machines already existed, but crucially, UNIVAC was programmable.
I find it interesting that one of the first customers to receive a Univac-I was the US Census Bureau.
Grace Hopper and her team first programmed the Univac-I in machine language, then developed higher level programming languages, The first language they developed was called FLOW-MATIC. Then they created COBOL, which is still in use today.
You can learn more about Grace Hopper and the history of computing at http://www.linuxvoice.com/history-of-computing-part-2/.