US State Legislature Election Results
State House (lower chamber) general-election results for 5297 legislative districts across 48 states, 1971-2018 -- Nebraska (unicameral, nonpartisan) and New Hampshire (large multi-member districts) aren't in this source.
Lower-chamber (State House / Assembly) two-party general-election results only, 1971-2018. The State Senate isn't built yet -- a planned future extension. See each state's page for sourcing detail.