New York Knickerbockers

The New York Knickerbockers were one of the first organized baseball teams which played under a set of rules similar to the game today. Founded as the "Knickerbocker Base Ball Club" by Alexander Cartwright in 1845, the team remained active until early 1870s.
In 1851, the New York Knickerbockers wore the first ever recorded baseball uniforms.
Origins and rules.
While a member of the volunteer Knickerbocker Engine Company No. 12, Alexander Joy Cartwright became involved in playing town ball (a similar game to baseball, and an older one) with the Gotham Club of New York at Murray Hill in Manhattan. In 1845, several members of the Gothams felt the club had grown too large for their "fastidious" tastes, and broke away to create an invitation-only ball club. They found a playing field, the Elysian Fields, a large tree-filled parkland across the Hudson River in Hoboken, New Jersey run by Colonel John Stevens, which charged $75 a year to rent. In order to pay the rental fees, Cartwright organized a ball club so that he could collect the needed money. The club was named the "Knickerbockers", in honor of the fire company where Cartwright was a member. The Knickerbockers club was organized on September 23, 1845. The first officers were Duncan F. Curry, president, William R. Wheaton, vice-president, and William H. Tucker, secretary-treasurer.
Creating a club for the ball players called for a formal set of rules for each member to adhere to, foremost among them to "have the reputation of a gentleman". Wheaton and Tucker formalized the Knickerbocker Rules, a set of twenty rules for the team:
It is likely that Wheaton picked some of his twenty rules based upon his previous experience in town ball play in Manhattan. According to his own account some fifty years later, his written rules for the Gotham Base Ball Club in 1837 eliminated "plugging" the runner and laid out the infield as a regular diamond. The twenty rules differed in several respects from other early versions of baseball and from rounders, the English game commonly considered the closest relative of baseball. "Two of these rules—the one that abolished soaking [putting a runner out by hitting him with a thrown ball] and the one that designated a foul as a do-over—were revolutionary, while the others gave the game a new degree of uniformity."
First "officially recorded" game and subsequent history.
The formation of the Knickerbockers club across the Hudson River created a division in the group of Manhattan players. According to Wheaton, "The new game quickly became very popular with New Yorkers, and the numbers of the club soon swelled beyond the fastidious notions of some of us, and we decided to withdraw and found a new organization, which we called the Knickerbocker." Membership in the Knickerbockers was by invitation and required the payment of dues; those Gothams or "New Yorks" who were excluded continued to play among themselves.
What was long considered the first "officially recorded" baseball game was played on June 19, 1846 at the Elysian Fields in Hoboken, New Jersey. The "Knickerbockers" and the "New York Nine" (also known as the New York Baseball Club, probably identical with the Gothams), played with Cartwright's twenty rules. Cartwright's team, the Knickerbockers, lost 23 to 1 to the New Yorks in four innings. Some say that Cartwright's team lost because his best players did not want to make the trip across the river. Cartwright was the umpire during this game and fined one player six cents for cursing.
The lineups for the teams were: 
However, there were several other recorded games prior to this. On October 6, 1845 the Knickerbocker Club played a 3 inning game between its own members, and on October 22, 1845 the "New York Club" beat the "Brooklyn Club" 24 to 4, with the box score included in the next day's morning newspaper.
Charles Schuyler De Bost, a catcher with the club for over 10 years, would be named club director in the mid 1850s. Over the next few years, the rules of baseball spread throughout the country. Baseball was becoming a popular sport with Americans and drew spectators by the thousands. The Knickerbocker rules would soon become part of the rules of the National Association of Base Ball Players in 1857. These rules slowly evolved into today's rules of baseball.
When the National Association of Base Ball Players was founded in 1858, the Knickerbockers began to lose their influence, and the club died out entirely in the early 1870s, after baseball had become thoroughly professionalized.
One century later, the Knickerbockers name itself was adopted by the New York Knickerbockers National Basketball Association team, although it is more commonly known by its shortened form, the Knicks.