Joseph Underwood was born in 1779 at Bermondsey, London, son of Thomas Underwood and his wife Mary, née Forster. 
ARRIVAL IN THE COLONY
Joseph Underwood arrived in New South Wales with his wife Charlotte and two sons on the Sydney Cove in June 1807. The SydneyCove was part owned by his brother James Underwood a former convict who arrived on the Admiral Barrington in 1791. The other owners being Henry Kable and Simeon Lord.
On board the Sydney Cove in 1807 were 109 female convicts and four boys. Free passengers included Mr. Mills of the Royal Navy who later became harbour master at Port Dalrymple, Mr. Samuel Foster and several other settlers. Sarah Bird arrived as a free passenger. Soldiers of the N.S.W. Corp. also came on the Sydney Cove.
Joseph Underwood brought with him letters of introduction and became a merchant in Sydney. He invested in the sealing industry and owned several vessels often joining them on voyages. One, the Campbell Macquarie was captained by Richard Siddons. Another, the Elizabeth and Mary which Joseph Underwood purchased from Thomas Abbott and Samuel Thorley in 1814, was used for many years to carry cedar and coal from the Hunter River.
Charlotte, the first wife of Joseph Underwood died in February 1818 and Joseph returned to England on the Surry in 1819 where he married Mrs Elizabeth Lang, who was the daughter of the emancipist John Harris.
Joseph Underwood abandoned his sea-faring life in 1820.
He was granted 1500 acres of land in 1821 . This land adjoined John Gaggin's grant and can be seen to the right on the map below. It is unlikely that Joseph Underwood ever resided on this grant and the land was claimed by James Mitchell in 1834.
In 1826 he purchased, for £670 the estate Melville,formerly a grant to William Hicks situated three miles from Wallis Plains. 
Joseph Underwood died in 1833 aged 54.
 Australian Dictionary of Biography - Joseph Underwood
 Index to map of the country bordering upon the River Hunter... by Henry Dangar (London : Joseph Cross, 1828). p15