The origins of spring training are lost in the shadows, like most of early baseball history. On an 1886 barnstorming tour of the South the Chicago White Sox were said to stopped off at Hot Springs, Ark., to basically sober up before the start of the season. Spring training is almost as old as baseball itself. The best evidence points to spring training first taking place in 1870, when the Cincinnati Red Stockings and the Chicago White Stockings held organized baseball camps in New Orleans. Other baseball historians argue that the Washington Capitals of the National League pioneered spring training in 1888, holding a four-day camp in Jacksonville. In a well-documented argument for spring training, Gus Schmelz, when managing the Cincinnati Red Stockings of the original American Association in 1888, petitioned team owner Aaron Stern to allow the team to train down south. It was a unique proposition: the players and the team would split the costs of training, and the two would also share in any profits. Though it was pitched more as a barnstorming tour than as an intense training session, Stern gave approval to the plan on the basis of it being a cheap way to figure out what veterans were expendable and what youngsters were worth keeping.
Still, most teams did not view spring training as being an activity that warranted out-of-town travel until barnstorming became an integral part of the equation. Most teams trained locally (indoors when the elements did now allow outdoor training), as it was cheaper for owners. When teams did train on the road, they combined workouts with exhibition games; many of these tours ran through Arkansas, Mississippi and Georgia, where the sight of a pro baseball players was still a novelty.
Spring training was not the big business back then as it is today. These were truly training camps designed to get players into playing shape. Typically most baseball players could not live year-round on their baseball salaries and took on other jobs that might or might not keep them in shape. Training camp was also a way to build team unity, though given the ornery temperaments of many ballplayers in this era, it's hard to argue that team unity was a huge factor.
By 1890 most teams were training on the road, although there were no organized spring-training leagues in the early days. Training camps were scattered in the South and the West, and teams spent as much time on the road returning home as they did in camp. A typical schedule would have players travelling between train stops at nights and playing games in the day. These games would be played against local colleges, semi-pro teams or another major-league team.
By 1910 spring training was a formalized institution, with most teams encamped east of the Mississippi. It was at this time the Grapefruit League became a formal league.