Hammond is a rural electorate east and south-east of Adelaide, covering 18,091 km2 (6,985 sq mi) in the east and upper south-east of the state, and takes in the towns of Callington, Cambrai, Coomandook, Karoonda, Langhorne Creek, Mannum, Nildottie, Peake, Pinnaroo, Purnong and Tailem Bend.

Hammond was created in the 1994 redistribution as a replacement for the electoral district of Ridley, and was first contested at the 1997 election.

Lewis briefly and unsuccessfully tried to have the electorate renamed in 1998 on the basis that Ruby Hammond had few ties to the electorate, proposing the revival of the name Murray-Mallee (which had covered most of Hammond's territory from 1985 to 1993), or if a ceremonial name was required, Unaipon, in honour of indigenous writer, preacher and inventor David Unaipon.

Lewis backed Labor to form government and was named as Speaker of the South Australian House of Assembly in return for his support.

Lewis attempted unsuccessfully to shift to the Legislative Council when it became clear that he had little-to-no chance of retaining the electorate at the 2006 election.