From SABR member Frank Jackson at The Hardball Times on January 25, 2019:
In angelology (yes, there is such a word), a seraph is the highest order of angel. The name was first used as a baseball nickname by a Los Angeles-based team in the short-lived California League in 1892. After that, Los Angeles teams were sans-Seraph. The Angels nickname took hold when the Pacific Coast League was founded and remained the nickname of choice through 1957, after which major league ball arrived in Los Angeles in the form of the Dodgers. The Angels nickname resurfaced in 1961 when the American League was granted an expansion franchise.
One can see why calling your team Seraphs a risky proposition. If your team wins a championship every year, great. If not …well, you’re asking for hoots and hollers from opposing fans. Better to just go with Angels, which covers you no matter where you rank in the league standings or the celestial pecking order.
In 1934, however, the Angels would have been justified in adopting the moniker Seraphs. That season the Angels were not only a team of the highest order in the Pacific Coast League, they were arguably the franchise of the highest order in all of minor league history. The team’s slogan for the 1934 campaign could have been “There’s a new Seraph in town.”
Read the full article here: https://tht.fangraphs.com/playing-ball-with-the-choir-invisible/