They proved their worth as a first division team in the 1911–12 season when they tied New York Clan MacDonald for second place.

The two teams met in a playoff for sole position of second, with Clan MacDonald winning 1–0.

[1] The next season, Celtic went on a streak of five straight league championships.

The Brooklyn Celtic was an American soccer club based in Brooklyn, New York that was an inaugural member of the reformed American Soccer League.

St. Mary's won their first (and only) National Cup in 1939 after beating Manhattan Beer 5–1 on aggregate over two legs.