I’m pretty sure Amherst was named after the town where it’s located, Amherst, Massachusetts, not a donor. The town was named after Jeffrey Amherst, 1st Baron Amherst of Montreal, a leading British military commander in the French and Indian War (Seven Years’ War) who engineered the capture of strategic forts at Ticonderoga, Niagara, and Quebec, and finally led the British capture of Montreal, ending French rule in North America. Amherst then was named Governor-General of British North America. Amherst College’s sports teams are called the Lord Jeffs. This has become very controversial because Lord Amherst ordered or knowingly approved the provision of smallpox-tainted blankets to indigenous tribes; there’s documentary evidence that Amherst knew of and approved the plan, but it’s disputed among historians whether the plan was actually carried out. Even if it didn’t happen, though, Lord Jeff’s role in the matter was despicable, and what he wrote about the plan and its intended victims clearly displays a white supremacist ideology and genocidal intent.
Lord Amherst died in 1797 at his estate in Kent, England. Amherst College wasn’t founded until 1821, though it was preceded by, and morphed out of, a secondary school called Amherst Academy which was founded in 1814. Both the academy and college were named after the town, and the town in Massachusetts is just one of numerous places in the U.S. and Canada named after Lord Amherst, including Amherstburg, Ontario (just south of Detroit); Amherst Island, Ontario; Amherst Island, Nunavut; Amherst, Nova Scotia, Amherst, Quebec; Fort Amherst on Prince Edward Island; Amherst, CO; Amherst, ME; Amherst, NE; Amherst, NH; Amherst NY (suburb of Buffalo); Amherst, OH; Amherst, SD; Amherst, TX; Amherst, WI; and Amherst County, VA.