The Los Angeles Lakers achieved a historic 33-game winning streak in the 1971-72 season, marking the longest consecutive wins across all four major North American sports leagues. This feat was accomplished despite Elgin Baylor's retirement early in the season and a strong performance by Jerry West, Wilt Chamberlain, and Gail Goodrich.
Source: https://sports.yahoo.com/yahoo-sports-am-the-election-and-college-sports-125606300.html