OurCampaigns seems to have complete results for the Alabama legislature as far back as 1974, though the district boundaries only go as far as 1994. Not sure about how well-reported the returns by county are. And, of course, the site navigation is a complete mess, so I'll put in some links:
STATE SENATE
STATE HOUSE
To change the date of perspective, use the thing on the top right (with the date input and "Set" button).
Thank you! I always forget how comprehensive OurCampaigns is because of how ugly and awkward the site is.