The Boston Athletic Association ice hockey team was an American amateur ice hockey team sponsored by the Boston Athletic Association that played in the American Amateur Hockey League, United States Amateur Hockey Association, and Eastern Amateur Hockey League. The team won the AAHL title in 1916 and 1917 and the USAHA championship in 1923, and the EAHL title in 1926. The team was nicknamed the Unicorn after the association's symbol.

Beginnings 1911–12

Following the construction of the Boston Arena, Boston Athletic Association athletic director George V. Brown pushed for the creation of a B.A.A. hockey team to play in the new building. Most of the initial members of B.A.A. club came from the Boston Hockey Club; an amateur team consisting of former Harvard players. Alfred Winsor was the B.A.A.’s first captain and head coach. Other members of the inaugural team were Skeets Canterbury, Trafford Hicks, George Peabody Gardner Jr., Ralph Hornblower, Howard C. “Old Doc” Leslie, Newton Foster, John Foster, Hatherly Foster Jr., Peter Sortwell, and John Heron.

The B.A.A. played its first game on November 17, 1911, against the Massachusetts Institute of Technology. The B.A.A. won 6–2.

The 1911–12 team scored victories against the St. Nicholas Hockey Club, Amherst Aggies, Montreal Westmount, New York Athletic Club, University of Ottawa, the Montreal AAA, tied the Intercolonials, and lost to McGill University, the Montreal Victorias, the Cleveland Athletic Club, and the Sherbrooke Canadiens. The B.A.A. and the Intercolonial hockey team played a best of five series for the Massachusetts hockey championship, which the Intercolonials won in four games. Afterwards, the B.A.A. played one additional game, which ended in an 8–6 victory over the Montreal Victorias.

1912–13 Hicks replaced Winsor as the captain for the 1912–13 season and Robert Clifford replaced Winsor as the starting center. Also joining the team this season were Forrest Osgood, Fred Huntington, and Harry Gardner.

The B.A.A. started their season on November 28, 1912, with a 7–5 victory over Harvard. The B.A.A. defeated MIT, St. Nicholas, Irish American Athletic Club, University of Toronto, St. Nicholas, McGill University, and Montreal AAA before losing their first game to the University of Toronto on January 16, 1913. The B.A.A. also dropped its next game to the Hobey Baker-led Princeton Tigers. They finished the season out with victories against the Montreal Victorias, Trois-Rivières, McGill University, Ottawa Stewartons, and Winnipeg All-Stars. The B.A.A. was scheduled to play the Sherbrooke Canadians on March 1, 1913, but refused to play.

1913–14 Charles L. Foote and Ollie Chadwick were added to the team during the 1913–14 season. The B.A.A. defeated regular opponents Harvard, St. Nicholas, University of Toronto, and MIT. They once again lost to Hobey Baker's Princeton Tigers. Games against the New York Wanderers and the Montreal AAA ended in ties, with the later game concluding at the end of the first half when Winsor unsuccessfully demanded a change of officials.

The 1913–14 season featured the first series between the B.A.A. and the city's other leading athletic club, the Pilgrim Athletic Association. The B.A.A. won the series two games to none.

American Amateur Hockey League 1914–15 On November 12, 1914, the B.A.A. was admitted to the American Amateur Hockey League, becoming the league's first team outside of New York City. Prior to the start of the season, Foote left the team to join an automobile ambulance corps and Sortwell was unable to play due to outside commitments. Hamlyn Robbins, Paul Smart, Stephen Hopkins, Dettmar Jones, and Jack Hutchinson began playing for the B.A.A this year. Fred Huntington was elected team captain.

Prior to the start of the AAHL season, the B.A.A. played a series of games against college teams. After losing to the University of Ottawa, they defeated the University of Toronto, Harvard, and Princeton.

The B.A.A. finished the AAHL season with a 6–2 record, good for second place in the five-team league.

The B.A.A. played a seven-game series against the city's other top amateur team, the Boston Arenas, which the Arenas won 4 games to 3.

1915–16

A second Boston team, the Harvard Club, joined the AAHL for the 1915–16 season. B.A.A. coach Alfred Winsor left to coach the Harvard Club and was replaced by Fred Huntington. Raymie Skilton, the star of the Boston Arenas the previous season, and Dartmouth goaltender Arthur Donahue, both joined the team for the 1915–16 season. Huntington also secured the services of some former high school players, including Cliff Peabody, Don Sands, Milton Stearns, and Sammy Wendell.

On December 22, 1915, Huntington, Harvard Club captain William Henry Claflin Jr., Arena Hockey Club manager Dr. Edward F. Murphy, and Boston Arena manager Walter Loguee organized a Boston Hockey League. The three teams would play a round-robin schedule of 12 games to determine the city champion.

On January 29, the B.A.A. defeated Yale 6–1 at the New Haven Arena.

The Boston Athletic Association and St. Nicholas Hockey Club both finished the AAHL season with 6–2 records and played a three-game playoff series to determine the champion. The first game was played on March 18, 1916, at the St. Nicholas Rink and was won 4–1 by the B.A.A. Game two was played a week later at the Boston Arena and drew a crowd of 5,000. St. Nicholas won 2–1 to tie the series. On April 1, the B.A.A. won the deciding game 7–0.

On April 5, the Arenas defeated the B.A.A. 4–2 to win the Boston League championship.

1916–17

After protracted negotiations, the B.A.A. and the Boston Arena reached an agreement on December 13, 1916, that would allow the team to play there for the 1916–17 season. As part of the agreement, the B.A.A. would receive an increase in the amount of money they received from the arena.

Huntington, Skilton, Donahue, Sands, Jones, and Hutchinson all returned for the 1916–17 season. They were joined by newcomers Leon Tuck and Frank Downing.

For the 1916–17 season, the AAHL was split into two divisions – one consisting of four teams from New York City (St. Nicholas, Brooklyn Crescents, the New York Hockey Club, and the Irish American Athletic Club) and the other consisting of three Boston teams (the B.A.A., the Arenas, and the Harvard Club, which had changed its name to the Boston Hockey Club).

On December 18, 1916, the B.A.A. and Harvard played a game that saw the teams use a total of 46 players (28 by Harvard and 18 by the B.A.A.). The B.A.A. won 6–0.

The B.A.A finished the regular season with a 4–3 record, which put them in second place behind the Arenas. To decide the league champions, the top two teams in each division played in a double round robin tournament. The B.A.A. beat the Arenas and Irish A.C. twice and split its series with the Crescents to win the AAHL title for a second year in a row.

B.A.A. drops hockey

On December 22, 1917, the Boston Athletic Association voted to abolish its hockey club. All of the team's members were serving in the armed forces and many were fighting with the American Expeditionary Forces in France. Instead, the B.A.A. elected to focus its efforts on promoting athletic programs in the area's Army camps during World War I.

The Boston Arena was partially destroyed by fire on December 18, 1918. It was rebuilt, and the new facility opened January 1, 1921.

Post-War return

In January 1920, the Boston Athletic Association returned to the ice as part of the Boston Amateur Hockey League, which consisted of the B.A.A., Harvard Club, Dartmouth Club, and Yankee Division. Due to destruction of the old Boston Arena, the teams played in the 1,100 seat Ice Pavilion in Cambridge. B.A.A. captain Jack Hutchinson was tasked with rebuilding the team. He, Willard Rice, Alphonse Lacroix, Gerry Geran, Frank Synott, Irving Small, Frank Downing, Sammy Wendell, Paul O'Sullivan, Dave Buttrick, Eddie Enright, Nelson Jost, Stanley Morton, and Wendell Reycroft would all suit up for the B.A.A this season.

On January 10, 1920, the B.A.A. defeated the Harvard varsity squad 5–4 in their first post-war game.

The B.A.A. defeated the Yankee Division 11–1, the Dartmouth Club 7–3, and Harvard Club 6–3 to win the Boston Amateur Hockey League's Pavilion Cup.

On March 13, the B.A.A. traveled to the Philadelphia Ice Palace, where they defeated the New Rochelle team 8–2.

Two of the B.A.A.’s players (Gerry Geran and Frank Synott) and one former player (Leon Tuck) played on the United States national hockey team at the 1920 Summer Olympics.

United States Amateur Hockey Association 1920–21

The B.A.A. was one of the founding members of the United States Amateur Hockey Association. Leon Tuck, who had come over from the Dartmouth Club, was chosen to serve as interim captain of the Unicorn squad. He had a large selection of players to choose from, with Hutchinson, Downing, Rice, LaCroix, and Morton returning and former college players Johnny Murphy, Dave Ingalls, and Joe Stubbs trying out. After the Harvard Club folded, George A. Percy, Gus Doty, Jack Wylde, and Alec Bright signed with the B.A.A. Tuck's former Dartmouth Club teammate Harris Murchie also joined the team. Before the season began, Tuck was named head coach of the Dartmouth Big Green men's ice hockey team and was replaced as captain by Percy.

The B.A.A. started the season with a non-league game against Harvard, which the Edward Bigelow-led Crimson won 4–1. Their first USAHA game took place two nights later and ended in a 3–1 victory over St. Nicholas.

The USAHA's two Boston teams – the B.A.A. and the Shoe Trades, played a best-of-five in-season series for the Winsor Cup. The B.A.A won the first two games before dropping the third 4–3. On February 17, the Boston A.A. defeated the Shoe Trades 5 to 3 in double overtime to win both the Winsor Cup and the group one championship. The final game was played under protest, as the Shoe Trade's leading scorer, George Dufresne, was declared ineligible by the league.

The Unicorn played the Cleveland Athletic Club in a four-game playoff, with the winner facing Eveleth for the league championship. The teams split the series, but Cleveland advanced on goal differential (10–8).

On March 22, 1921, league president William S. Haddock reversed his decision regarding Dufresne's eligibility and ordered that the B.A.A. and the Shoe Trades play once again. If the Shoe Trades won, they would play Eveleth in a four-game series with the winner advancing to face Cleveland. On March 26, 1921, the Boston Athletic Association defeated the Shoe Trades 4–3, eliminating them from championship contention.

The B.A.A. also played a series of games against Canadian teams. They defeated La Tuque and Queen's College and lost to the Winnipeg Hockey Club and the Toronto Aura Lee (the latter team beating the B.A.A. twice).

1921–22

The B.A.A. added Ned Bigelow, Justin McCarthy, Harry Snelling, Bobby Emmons, and Carl Stillman to play alongside returning players Percy, Hutchinson, Ingalls, Rice, Bright, Stubbs, Doty, and LaCroix. Dave Ingalls was the team captain this season.

They started the 1921–22 season with two exhibition games against Harvard University and a contest against the Sudbury Wolves, all of which were won by the Boston Athletic Association.

Before the start of the USAHA season, a four-team tournament was held to determine which three Boston teams would make the league. The B.A.A. defeated the Melrose Hockey Club, a new team made up mostly of players who had never played club hockey before, 7–0. In the final game, the Unicorn lost to the Westminster Hockey Club 2–1. Pere Marquette defeated Melrose in the consolation game to claim the final spot. The B.A.A. finished the USAHA season with a 5–3 record, losing the eastern division to the Westministers.