Often, N-e-g-r-o League teams would get their names by placing the word "Black" in front of the name of the local MLB or MiLB team, i.e. New York Black Yankees, Chattanooga Black Lookouts, Atlanta Black Crackers ("Crackers" was the name of the first professional team in Atlanta, a reference to cracking home runs), Birmingham Black Barons (who at one time counted Satchel Paige and Willie Mays among their players and were owned by Abe Saperstein, the same man who founded and owned the Harlem Globetrotters), Washington Black Senators, Jacksonville Black Caps (Jacksonville's MiBL team was the Red Caps) Shreveport Black Captains, New Orleans Black Pelicans, Little Rock Black Travelers,etc. The Kansas City Royals name is a tribute to the most famous N-e-g-r-o League team of them all, the Kansas City Monarchs.

When the MLB and MiLB teams were on road trips, the N-e-g-r-o League teams would often play in their stadiums and give the MLB team owner a portion of the receipts. This was also true for some MiLB teams. For example, when the Birmingham Barons were on a road trip, the Birmingham Black Barons would play at Rickwood Field. The N-e-g-r-o League teams were, however, required to use the MLB or MiLB teams announcers who were often just as racist as the owners. When the Barons played at Rickwood Field there was one section of the right field bleachers that was designated as "The Colored Section" and whenever a player be it a member of the Barons or the opposing team would hit a home run into that section the announcer would say the player hit it into "The Coal Bin." The bleacher designations were the exact reverse for the Black Barons' games, with one difference: the one section of the bleachers had no denigrating designation.

In short, the N-e-g-r-o Leagues showed that we could do anything that Whites could do and could do it just as well, if not better in some cases. The N-e-g-r-o Leagues endured until 1962 when they finally closed down shop for good because they had served their purpose, which was to give us a place to play professional baseball. When Pumpsie Green debuted with the Red Sox in 1959, it meant that every team in MLB had integrated.

Before anyone says anything about the date in the question it is correct. Jackie Robinson signed to play with the Brooklyn Dodgers' minor league team, the Montreal Royals in early 1946. He played one year for them before being called up to the Dodgers with whom he debuted on April 15, 1947.