In the later part of (the 1872 season) amateur base ball received quite an impetus through the inauguration of the early closing movement among mercantile and other business houses on Saturday afternoons, whereby the employees of these firms were brought into organized clubs named after the firms by whom they were employed, such as the "Dodd, Brown & Co.," "Crow, McCreery & Co.," "Sam. C. Davis & Co." Clubs and others of like nature. In those clubs some fine base ball talent was developed that took a more tangible existence and permanency in '73.-E.H. Tobias, writing in The Sporting News, January 4, 1896
...The Mercantile community also took a deeper interest and more widespread participation in the game (in 1873) and so numerous were the matches played by the representatives of business concerns that it will be impossible in this history to do more than give such games the briefest passing notice.
The Early Closing Movement was in many ways a companion to the more familiar movement for an eight hour work day and a five day work week and can be seen as part of the general Short-time movement. The main differences in the movements is that while the latter was pushed by labor organizers, socialists, anarchists, etc. and in the end required government action to implement, the Early Closing Movement originated with more moderate progressive elements, relied on the co-operation of business owners, and was focused almost entirely on retail shops.
The goal of the Early Closing Movement, which most likely originated in England in the 1840's and spread to the United States, Canada, and Australia in the later part of the 19th century, was simply to have stores close early on Saturdays so that clerks and workers of the stores could have more time off for recreation. In 1890, George Howell wrote about the movement in The Conflicts of Capital and Labor and summarized the argument for closing early on Saturdays:
Excessive work, whether from long hours, or from overwork while engaged in it, is disastrous morally and socially, as well as mentally and physically, and at the same time, by its exhaustive process, it really diminishes the productive power of the worker.
An article in an 1883 edition of The Banker's Magazine speaks to the success of the movement and states that it was not uncommon to find towns where ninety percent of businesses closed early for the "Saturday half-holiday." The author of the article goes on to answer the question of why the movement has been so successful:
The answer naturally comes, that the tradesman wishes to have an opportunity for recreation and amusement which the hours of his business prohibit him enjoying on the ordinary days of the week...The masters...(and) man of figures...regards the early closing one day in the week as a good investment, and one which will bring him in large returns.
The effects that the Early Closing Movement specifically and the Short-time movement in general had on baseball, I think, are self-evident. Tobias touches on it in his writings. Closing the shops early on Saturday expanded not only the pool of available players but also the number of people who could come to a match. Tobias had written about a general decline in interest in the game in St. Louis in the early 1870's and implies that one of the positive effects of the success of the Early Closing Movement was to help revive interest in the game. I have no doubt that the Short-time movement had similar effects across the country and baseball as a business benefited from, and most likely supported, the movement.
Note: All the businesses mentioned by Tobias at the top of this post were retailers. Dodd, Brown & Co. sold "silk and fancy goods." Crow, McCreery & Co. was a dry goods store. Sam. C. Davis & Co. sold dry goods and groceries.