Today, Google, Apple, Bosch, Facebook, Uber, Nokia, Autodesk, and IBM are among 1,600 technology firms generating .7 billion in annual Pittsburgh payrolls.The area has served as the long-time federal agency headquarters for cyber defense, software engineering, robotics, energy research and the nuclear navy. "Be it enacted by the Pennsylvania State Senate and Pennsylvania House of Representatives of the Commonwealth of Pennsylvania..the authority of the same, that the said town of Pittsburgh shall be...erected into a borough, which shall be called the borough of Pittsburgh for ever." The error was repeated commonly enough throughout the rest of the 19th century that the original pronunciation was lost and in 1890 the "h" was removed in order to make it easier to spell.
In the 1830s, many Welsh people from the Merthyr steelworks immigrated to the city following the aftermath of the Merthyr Rising.
By the 1840s, Pittsburgh was one of the largest cities west of the Allegheny Mountains.
Michael Bezallion was the first to describe the forks of the Ohio in a 1717 manuscript, and later that year European fur traders established area posts and settlements.
During 1753–54, the British hastily built Fort Prince George before a larger French force drove them off.
Lord Jeffrey Amherst ordered blankets contaminated from smallpox victims to be distributed in 1763 to the tribes surrounding the fort.
The disease spread into other areas, infected other tribes, and killed hundreds of thousands.
During Pontiac's Rebellion, native tribes conducted a siege of Fort Pitt for two months until Colonel Henry Bouquet relieved it after the Battle of Bushy Run.
Fort Pitt is notable as the site of an early use of smallpox for biological warfare.
Fort Pitt (now Pittsburgh) at the source of the Ohio River became the main base for settlers moving into the Northwest Territory.
The War of 1812 cut off the supply of British goods, stimulating American industry.
By 1815, Pittsburgh was producing significant quantities of iron, brass, tin, and glass.