BRADDOCK, a borough of Allegheny county, Pennsylvania, U.S.A., on the Monongahela river, Iom. S.E. of Pittsburgh; served by the Baltimore and Ohio, the Pennsylvania, and the Pittsburgh and Lake Erie railways. The population in 1920 was 20,870, 6,415 foreign-born white; 193o, 19,329. With the adjoining boroughs of North Braddock and Rankin it forms one community, an im portant industrial centre, which in 1927 had a population es timated at over 5o,000, and an assessed valuation of over $42,000, 000. The manufacture of steel is the basic industry. The first settler was John Frazier, in 1742, whose cabin was the first built by a white man west of the Alleghenies. It was here that General Edward Braddock in was defeated and mortally wounded in an engagement with the French and Indians; and here on Aug. I, 1794, 8,000 men gathered in peaceful protest against the new federal tax on whiskey. The borough was incorporated in 1867.