Complex sentence: It was built as a suburban villa in 1760 in what is now the Nicetown neighborhood of the city, and housed Catherine Mallon's Boarding School for Girls from 1806 to 1824.
Split into simpler sentences: It was built as a suburban villa in 1760 in what is now the Nicetown neighborhood of the city. It housed Catherine Mallon's Boarding School for Girls from 1806 to 1824.