In 1940, R.R.M. (Bob) Carpenter brought professional baseball back to the city with the original Wilmington Blue Rocks. The team was a Class B Interstate League affiliate of the Philadelphia A's. Hall-of-Famer Connie Mack owned the Blue Rocks for their first four years of existence. Another Hall-of-Famer, Chief Bender, served as the Blue Rocks first manager.
In 1943, Carpenter, who was a partner with Mack since the Blue Rocks' inception, took full ownership of the club. For their final nine years, the original Blue Rocks were a Philadelphia Phillies affiliate.
The nickname "Blue Rocks" came from 73-year-old Robert Miller in a name-the-team contest. Miller lived in the Henry Clay section of the city, famed for its blue granite found along the Brandywine River.
The Blue Rocks played in Wilmington Park, a $185,000 facility at 30th Street and Governor Printz Boulevard. At the time, it was considered one of the finest minor league parks in the country.
In Wilmington's 13 years in the Interstate League, the Blue Rocks won four Governor's Cup titles and missed the postseason only twice. Pitchers Robin Roberts and Curt Simmons and outfielder Elmer Valo were some of the notables who played for the Blue Rocks before going to the major leagues.
After setting many records for attendance, the Blue Rocks' fan support dwindled and 1952 was their final season in the Interstate League.
In 1993, the Blue Rocks returned to professional baseball as the Class-A Carolina League affiliate of the Kansas City Royals. The franchise, formerly known as the Peninsula Pilots, was moved from Hampton, VA.
The stadium, built by the construction company of Blue Rocks President Matt Minker, was named Legends Stadium (later changed to Judy Johnson Field at Daniel S. Frawley Stadium).
Like their forerunners, the modern Blue Rocks have enjoyed great on-field success. Since their return in 1993, Wilmington has one of best winning percentages in all of Minor League Baseball, winning eight Northern Division titles in 12 years and four Carolina League championships.