The Providence Grays baseball club was Rhode Island's only major league baseball team, competing in the National League from 1878 to 1885. Playing their home games at the Messer Street Grounds, the Grays were one of the best teams in the National League's early days, compiling a record of 438-278 (.612) and won baseball's first World Championship.

The team was led in early years by outfielder "Orator" Jim O'Rourke and pitcher John Montgomery Ward, both Hall-Of-Famers. The Grays won the National League championship in 1879, the league's second year, besting the Boston Red Caps by five games. O'Rourke would defect to Boston after that season, but Providence continued their success behind "Old Reliable" Joe Start and a new pitcher by the name of Charlie "Old Hoss" Radbourn.

The 1884 season was the most memorable for the Grays. It was in that year that the National League had agreed to a three game championship with their rival, the American Association. Providence, led by pitchers Radbourn and Charlie Sweeney, was expected to compete with the Boston Red Stockings for the National League crown. Radbourn had established himself as one of the league's premier pitchers, winning 106 games the previous three seasons, including a record 48 in 1883. Sweeney was the up-and-comer, regarded so highly that he was picked to start on Opening Day.

When the Red Stockings came to town in June however, they were comfortably ahead of the Grays in the standings, and the word was out that the 29-year-old Radbourn was finished. He had pitched over 1400 innings in the last three years, and his arm was limp and tired. In his previous start Radbourn had given up twelve runs, and in the meantime Sweeney was rolling over the competition.

Radbourn pitched well against Boston, but was benched just a game later for violating the team's temperance pledge. Sweeney struck out 19 batters that day, and was the toast of the team. Strange things were afoot in the clubhouse, however.

1884 was the first and only year of the upstart Union Association, a league started by angry owners to compete against the National League and the American Association. The UA was a "player friendly" league, offering free agency almost 100 years before Curt Flood struck down the Reserve Clause. The league was fairly successful in drawing talent from the other leagues, and rumor had it that Radbourn was pitching ineffectively in an attempt to get himself fired. He would then be free to sign with whoever he wanted.

On July 16th Radbourn was suspended by the team for intentionally pitching poorly. A local newspaper came forth with allegations that Radbourn had already signed with the St. Louis franchise of the UA for a then-unheard-of $5,000. Four days later, Charlie Sweeney was banned from the league for walking off the field in the middle of a game. The next day he was in St. Louis, and Radbourn was hastily reinstated.

Radbourn offered to pitch every game for the rest of the season in exchange for being paid Sweeney's salary on top of his own. In a critical four game stretch in August, he won four straight games against Boston, giving up only one run over more than 36 innings. At one point, the Grays rattled off twenty straight victories, and Radbourn was 31-2 after Sweeney's defection.

Radbourn finished the season 59-12, setting a single season records for wins that still stands today. The Grays meanwhile, won the league running away. The closest team, Boston, was 10 ½ games back. No one else was within 19 games. The Grays then whipped the New York Metropolitans, winning all three games in the championship.

Despite the Grays' success, the team was never much of a draw, and in 1885 the team disbanded. A minor league team with the same name played from 1891 to 1929, featuring a young pitcher named Babe Ruth. After that, professional baseball would not return to Rhode Island until the minor league Pawtucket Red Sox began play in 1942.