Grantham is an English town in the South Kesteven district of Lincolnshire. It straddles the London–Edinburgh East Coast Main Line and the River Witham and is bounded to the west by the A1 north–south trunk road. It lies about 23 mi south of the county town, Lincoln, and 22 mi east of Nottingham. The population in 2016 was put at 44,580. Grantham is known as the birthplace of UK Prime Minister Margaret Thatcher, for educating Isaac Newton at the King's School, as the birthplace of the UK's first female police officer, Edith Smith in 1914, and for making the UK's first running diesel engine in 1892 and tractor in 1896. Thomas Paine worked there as an excise officer in the 1790s.