As America turns 250, a rare 1790 exchange between Washington and Bishop Carroll takes on new relevance

As the United States prepares to celebrate its 250th anniversary, historians are looking back at the founding-era documents that helped define the nation's earliest ideals. 

Among them is a little-known 1790 exchange between John Carroll, the first Catholic bishop in the United States, and President George Washington — a correspondence that helped answer a fundamental question facing the young republic: Could Catholics, long viewed with suspicion under British rule, truly become equal American citizens?