Complex sentence: Also known as the Browns, St. Louis established themselves in 1882 as the dominant team in the American Association (AA), joined the NL in 1892 and adopted Cardinals as their official name in 1900.
Split into simpler sentences: Also known as the Browns before becoming the Cardinals, St. Louis established themselves in 1882 as the dominant team in the American Association (AA). They joined the National League in 1892 and adopted Cardinals as their official name in 1900.