Complex sentence: As a result, the Riverside Historic District, Jacksonville's first historic district, was added to the National Register of Historic Places in 1985, and today comprises 6870 acres and contains 2120 historical buildings.
Split into simpler sentences: As a result, the Riverside Historic District, Jacksonville's first historic district, was added to the National Register of Historic Places in 1985. The Riverside Historic District comprises 6870 acres and contains 2120 historical buildings.