Question: When was the Australian suburb founded in the district named after Thomas Elder founded on the banks of the Strut River?
Sentence (from "Electoral district of Elder"): Elder is a 15.7 km² urban electorate in Adelaide's south-west, taking in the suburbs of Ascot Park, Clovelly Park, Marion, Melrose Park, Mitchell Park and Park Holme, and parts of Colonel Light Gardens, Daw Park, Edwardstown, Oaklands Park, Plympton Park, South Plympton and Warradale.
Relevant evidence: Yes