Birmingham Township is a township in Chester County, Pennsylvania, United States. The population was 4,081 at the 2020 census. Birmingham Township was the site of the Battle of Brandywine, September 11, 1777, during the American Revolutionary War. Over 18,000 men were engaged. Until then, it was the largest land battle on the North American contin…Birmingham Township is a township in Chester County, Pennsylvania, United States. The population was 4,081 at the 2020 census. Birmingham Township was the site of the Battle of Brandywine, September 11, 1777, during the American Revolutionary War. Over 18,000 men were engaged. Until then, it was the largest land battle on the North American continent. Birmingham Friends Meeting, founded in 1690, is the location of a common grave of both American and British casualties. Much of the original battlefield around the meeting is preserved to this day. Birmingham is the oldest township in Chester County. Philadelphia magazine recently rated the township as one of the top five Best Places to Live in the suburbs of Philadelphia and as the "Place with the Biggest Paychecks".