In October 1954, Robert "Red" Kramer received a phone call from his friend, Jim Fyfe. They discussed and agreed that there was a need to start a youth baseball league on Youngstown's westside. They also agreed the league should provide the opportunity for all players to play, not just the best players. As a result, they formed a league that was the first in the area to have a must play rule for all players in every game and that required that once a player made a team's roster, he could not be cut in subsequent years.

The Mill Creek Junior Baseball League began play in 1955 with six teams. Its games were played at Boardman Park. In 1957 games were to moved to the Mill Creek Park Department operated fields at Kirkmere playground (now Scholl playground), a more convenient location on Youngstown's westside. In two years the league had grown to twelve teams.

Incorporated in 1965, the league was growing, and so were its resources. But one thing was still missing. The league did not have its own fields. In 1967, Sinclair Oil Company agreed to lease property to league for $1 a year. The property was located at the intersection of Schenley Avenue and Bears Den Road. The league immediately constructed two little league fields (fields #1 and #2) and one pony league field (field #3) on the property, and they were ready for play for the 1967 season.

In 1972, a meeting hall was built (now called Kramer Hall) adjacent to field #1, which also served as a concession stand. Lighting was added to fields #1 and #2 in 1973, and in 1992 lights were added to the Pony field. Responding to the growing interest of girls in baseball, a girl's softball league was added in 1974.

The generous lease arrangement ended in 1976, when Sinclair's successor, Arco, required that the league purchase the property. The league did so for $45,000. In 1986, the finest youth baseball concession stand in the area was added to the facilities between Fields #1 and #2. In 1987 the fields' name was changed from Arco Fields to Kramer Fields, in honor of Red Kramer, the league's founder and longest serving President.

In 2003, the league joined Babe Ruth Baseball, a national youth baseball organization, participating in the boys 11-12 year old Cal Ripken division. In its first year of participation, the Mill Creek 11-12 year old boys' all-star team won the 2003 Cal Ripken State Championship.

No discussion of the league's history would be complete without mention of the league's annual All-Star Tournament. Started in 1968, the tournament has featured the best boys and girls players form throughout the greater Youngstown area. Running over the last three weeks of July, boys' teams from New York and Pennsylvania have participated over the years. In 1992 the tournament's name was changed to the "Chuck Acri Memorial Tournament", in honor of a longtime league contributor.

Since its inception in 1955, the league has continued to grow. As of 2004, the league is now fielding fifty two boys and girls teams, comprised of a total of over 700 players.