Stanford engineering graduate Harry Williams entered the coin-operated amusement industry in 1933 and helped popularize several important pinball innovations such as the tilt mechanism, electrically-powered scoring holes, and the ability to win a free play by achieving a certain score. After working for a succession of companies including Pacific Amusement Manufacturing, Rock-Ola, and Exhibit Supply, he went into business with Lyndon Durant in 1942 under the name United Manufacturing. After a break with Durant, Williams founded the Williams Manufacturing Company in 1943 at 161 West Huron Street in Chicago, Illinois. The first seven products were a fortune-telling machine called "Selector Scope" (1944), two electro-mechanical (EM) games, "Periscope" (1944) and "Liberator" (1944), a novelty called "Zingo" (1944), a pinball conversion called "Flat-Top" (1945), another EM arcade game, "Circus Romance" (7/45) and a second pinball conversion called "Laura" (1945). The two pinball conversions (Flat-Top & Laura) were built by purchasing older pinball machines made by other companies and changing artwork and other elements on the playfield. The lack of raw materials during World War II made the manufacture of new machines difficult and expensive. The first all original amusement device made by Williams was a flipperless pinball machine called "Suspense" (1946). During the late 1940s and early 1950s, Williams continued to make pinball machines and the occasional bat-and-ball game. In 1950, Williams produced "Lucky Inning", their first pinball machine to have its bottom flippers facing inward in the modern manner.