William Johnson is thought to have originally planned a mercantile or legal career, but in 1738 he emigrated to America to manage land granted to his uncle, Admiral Sir
Peter Warren. Settling in
Upstate New York along the Mohawk River, he built
Fort Johnson, a home and business center which also provided protection for local settlers. He learned from and lived with the
Mohawk Indians, who adopted him and later made him a civil chief (sachem). He also began to purchase land from the Indians in his own right.
Johnson was appointed Superintendent of Indian Affairs by the British, and later became a
Major General in the
British forces during the
French and Indian War. As a reward for his services, he was granted additional tracts of land in what is now
Hamilton and
Fulton counties. In 1762, he founded the city of
Johnstown about 25 miles west of
Schenectady, New York. The city, originally called John's Town, was named by Johnson for his son, John. Ten years later, Johnstown became the county seat of
Tryon County when Johnson convinced
William Tryon, the British Governor of New York, to separate the western portion of the state from Albany County making Johnstown and the surrounding area a separate county named for Governor Tryon.
In 1764, Johnson, "by virtue of the powers and authority to him given by his Majesty" the king of England, signed a friendship and peace treaty with four delegates representing the
Hurons of
Detroit.
Having begun as an Indian trader, Johnson soon became one of New York's most prosperous and influential citizens. His business interests came to include various enterprises including a lumber business and a flour mill. In acknowledgment of Johnson's successful business endeavors, the local Native American inhabitants dubbed him "Warragghivagey," or "he who does much business." Johnson's businesses, perhaps most particularly his lumber operations, benefitted from slavery, which was then legal in New York State. As the largest slaveholder in the county and perhaps in the state of New York, he had some sixty slaves working for him.