Describe Calpurnia's church. How did the church get its name?

The inside of Calpurnia's church is described as being without a ceiling and unpainted. The church is lit with kerosene lamps, and the congregation sat on pine benches. First Purchase had no organ, piano, hymn-books or church bulletin. The church was named First Purchase because its construction was paid for by the first earnings of freed slaves.

It was an ancient paint-peeled frame building, the only church in Maycomb with a steeple and bell, called First Purchase because it was paid for from the first earnings of freed slaves.