Boston Capital became one of the largest apartment owners in the US with a little help from Uncle Sam. Boston Capital takes advantage of federal tax credits, which it packages into public investment funds in exchange for developing apartment complexes targeted at low-income tenants. Subsidiary Boston Capital Finance originates construction and mortgage loans for low income housing developments its parent owns. The company, founded in 1974, has a controlling interest in about 168,000 apartments in 48 states, Puerto Rico, and the US Virgin Islands.