Governor Lachlan Macquarie wished to honour one of his magistrates who had died in the course of serving the community of Windsor during the October floods of 1810. Andrew Thompson was born in Jedburgh, Scotland in 1773, convicted of setting fire to some straw when 16 years of age and transported to New South Wales on the Pitt in 1792. He proved to be an industrious person, making the Hawkesbury district his home with a grant of one acre of land at the Green Hills (Windsor) in 1799. Governor King appointed Thompson as Chief Constable of the Hawkesbury District in 1802, and granted him 278 acres of farmland in 1804 along the Nepean River which Thompson named Agnes Banks in memory of his mother. Governor William Bligh had a 250 acre property on the Hawkesbury River to the north of Green Hills and Andrew Thompson successfully managed this farm named ‘Blighton’. The farms along the Nepean and Hawkesbury Rivers were subject to seasonal flooding and in 1806 Reverend Samuel Marsden publicly praised Thompson for his rescue work. The rebel government that removed Bligh from the office of governor also dismissed Thompson from his position of Chief Constable.
Governor Lachlan Macquarie arrived in January 1810 and immediately reversed all the decisions taken by the rebels during 1808 and 1809, thus reinstating Andrew Thompson. In October the colony was subject to torrential rain and the Hawkesbury valley severely flooded. Andrew Thompson used his boat to rescue over one hundred people, exhausting him in the effort. He died after two days on 22nd aged only 37 years. Macquarie ordered the burial site in St Matthew’s Church of England cemetery be covered with a specially carved stone (pictured) honouring the man. He also designated the centre of the town of Windsor to be named Thompson Square.