Single-A
Single-A, formerly known as Class A and sometimes as Low-A, is the fourth-highest level of play in Minor League Baseball in the United States, below Triple-A, Double-A, and High-A. There are 30 teams classified at the Single-A level, one for each team in Major League Baseball (MLB), organized into three leagues: the California League, Carolina League, and Florida State League. == History == Class A was originally the highest level of Minor League Baseball, beginning with the earliest classifications, established circa 1890.