Indigenous peoples lived on the shoreline and bluffs for thousands of years, and the Sommerheim Park Archaeological District west of the city holds artifacts from about 8,000 BCE to 500 CE. The French built Fort Presque Isle near present Erie in 1753 to defend New France against the British. Presque-isle, "almost an island," refers to the peninsula now protected as Presque Isle State Park. When the French abandoned the fort in 1760, it was their last post west of the Niagara River, and the British garrisoned it the same year.
More about Erie
After the Revolution, New York, Pennsylvania, Connecticut and Massachusetts all claimed the Erie Triangle, 202,187 acres fronting Lake Erie. On January 9, 1789, Iroquois representatives signed a deed giving up the land for $2,000 from Pennsylvania and $1,200 from the federal government, and the Seneca settled their claims against Pennsylvania in February 1791 for $800. The triangle became part of Pennsylvania on March 3, 1792, when the other states gave up their rights and sold it for 75 cents an acre, $151,640.25 in all.
The legislature ordered a survey near Presque Isle on April 18, 1795, and Andrew Ellicott, who had finished L'Enfant's survey of Washington, D.C., arrived in June to lay out the town. Settlement began that year, when Lieutenant Colonel Seth Reed and his family came from Geneva, New York. Erie's nickname, the Flagship City, comes from its role as home port of the Niagara, Oliver Hazard Perry's flagship.
Sources
Wikipedia: Erie, Pennsylvania