He was a cousin of the noted animal painter Sir Edwin Landseer, who sculpted London's famed Trafalgar Square lions.
[2] Landseer started a business as a small building contractor for a time before joining the gold rush to Forest Creek, Victoria, about 1850; he was successful there and subsequently on occasional journeys to other goldfields.
He also had extensive interests in flourmills in Milang and elsewhere on Lake Alexandrina, and he owned barges and river steamers, including Bourke, Dispatch, Eliza, Gertrude and Industry.
[2] Landseer was elected in 1875 to the South Australian House of Assembly as the senior representative in the multi-member electoral district of Mount Barker.
[2]Landseer was probably too inflexible on matters of principle to succeed in government: his private correspondence reveals distaste for the sharp practices of politics and a refusal to countenance underhand activity on his behalf.
[9] After Landseer's resignation from parliament in 1899, his health was undermined by rheumatism and, later, heart disease; and his fortune by the decline of the river trade and reckless speculation in the Western Australian gold boom.