Was the Federal League a Major League?

1915 Federal League Scorecard

"Was the Federal League of  a major league? Baseball authorities interested in the answer have been, and still are, divided in their opinions. Could a six-team independent league in 1913, generally regarded as no better than Class D, become an eight-team organization of major league quality a year later? The odds suggest that even the thought was preposterous. And yet, the historical background suggests that we ought not reach hasty, unwarranted conclusions. In simplest terms that historical background began in 1912. That year two attempts were made to start independent leagues without the blessings of the National Association of Professional Baseball Leagues. The United States League, composed of eight eastern cities, survived only a month and the Columbian League, made up of cities in the Midwest, didn't even open the season. In 1913 the United States League opened the season but folded after only three games. The midwestern organization, rechristened the Federal League with John T. Powers as its president, not only opened as a six-team league but completed a 120 game season. Chicago, Cleveland, Covington, Indianapolis, Pittsburgh, and St. Louis had teams in that loop."
SABR

The Federal League of Base Ball Clubs: The History of an Outlaw Major League, 1914-1915 (review)
"When the newly proposed United Football League was presented for public scrutiny in 2009, its innovative features (e.g., Thursday and Friday night games) and propensity to go head-to-head with the firmly established National Football League raised many eyebrows. And yet, almost one hundred years earlier the upstart Federal League of Base Ball Clubs set many precedents for the outlaw leagues in professional sports that followed. Wiggins's detailed account of the Federal League (1914-15) chronicles the history of this ill-fated venture for baseball fans of today. .."
Project MUSE

"The last independent major league ended its brief run in 1915, after only two seasons at the national pastime's top level. But no competitor to establishment baseball ever exerted so much influence on its rival, with some of the most recognizable elements of the game today--including the commissioner system, competition for free agents, baseball's antitrust exemption, and even the beloved Wrigley Field--traceable to the so-called outlaw organization known as the Federal League of Base Ball Clubs. This comprehensive history covers the league from its formation in 1913 through its buyout, dissolution, and legal battles with the National and American leagues. The day-to-day operation of the franchises, the pennant races and outstanding players, the two-year competitive battle for fans and players, and the short- and long-term impact on the game are covered in detail."
amazon - The Federal League of Base Ball Clubs