Robinson was born on 17 December 1785 in a log cabin in the area soon to become Allegheny. He was reputedly the first white child born west of the Allegheny River. His parents were James Robinson, who operated a ferry across the river, and Martha Boggs Robinson. William was styled "Junior" to distinguish him from an uncle of the same name. After schooling at Pittsburgh Academy and Princeton, he read law under ex-senator James Ross, but did not go on to practice the profession. In 1806, on a flatboat trip down the Ohio River, the young Robinson and several companions were detained on suspicion of taking part in the Aaron Burr conspiracy to found a Southwestern empire. They were released as nothing treasonous could be proven against them.
Business
Robinson managed a number of companies over his lifetime. He was the first president of the Allegheny Bridge Company, which built a bridge over the Allegheny River at what is now Sixth Street. Opened in 1819, the bridge was the first to cross the Allegheny at Pittsburgh. Robinson was the first president of the Ohio and Pennsylvania Railroad, which became part of the Pittsburgh, Fort Wayne and Chicago Railway, a major component of the Pennsylvania Railroad system. He served for 16 years as the first president of the Exchange Bank of Pittsburgh. He was also partner in one of the area's early rolling mills.
Politics
Robinson was elected as a Democrat to the Pennsylvania House of Representatives, serving from 1833 to 1834. When Allegheny borough became a city in 1840, Robinson, then a Whig, became its first mayor. His other positions in the Allegheny government included treasurer, assessor, and president of Select Council. According to one historian, Robinson had a "haughty and dictatorial" manner that hampered his political ambitions.
The Mexican War Streets neighborhood, originally called Buena Vista, was established by Robinson on part of his extensive land inheritance from his father. He laid out the plan in 1847 during the Mexican–American War, naming the streets for the war's battles and leaders. Contrary to legend, he saw no active service in the conflict.
State militia
In 1849, Robinson was elected major general of the 18th Division, Pennsylvania Volunteers, resulting in his being known afterward as "General" Robinson. The Volunteers at the time were a more social than military organization.