Question: What is the nickname for the founder of the independent semi-professional American football team J.P. Rooneys?

Context paragraphs:
Watertown Red &amp; Black: The Watertown Red & Black is a semi-professional American football team based in Watertown, New York.  Founded in 1896, the team is the oldest semi-pro football team in the United States.  Because of this, the team has the most wins (565), losses (268), ties (43) and games played (876) of any semi-professional team; their overall win percentage is .670.

Arizona Assassins: The Arizona Assassins were a women's semi-professional American football team founded in 2010.  The Assassins were members of the Women's Football Alliance.  Based in Gilbert, Arizona, the Assassins played their home games on the campus of Washington High School (Phoenix, Arizona).

Art Rooney: Arthur Joseph Rooney Sr. (January 27, 1901 – August 25, 1988), often referred to as "The Chief", was the founding owner of the Pittsburgh Steelers, an American football franchise in the National Football League (NFL), from 1933 until his death.  Rooney is a member of the Pro Football Hall of Fame, was an Olympic qualifying boxer, and was part or whole owner in several track sport venues and Pittsburgh area pro teams.  He was the first president of the Pittsburgh Steelers from 1933 to 1974, and the first chairman of the team from 1933 to 1988.

New England Football League: The New England Football League (NEFL) is a semi-professional American football league based out of Salisbury, Massachusetts and owned by Thomas Torrisi.  It is the largest semi-professional league in the region.  The NEFL was founded in 1994 and was also known as the Greater Lawrence Men's Football League.  It currently consists of 40 teams with about 2,000 players playing in three different classifications (A, AA, AAA) with at least two teams based in each of the six New England states.  The league provides competitve football for adult players.  It is a "working man's league" as most players have regular jobs during the week.  Teams practice on weeknights and play on the weekends, most games on weekends.  Players don't get paid for their participation, but they often pay $200 to be on the team's roster.  The league runs from spring until October.  Each team can dress up to 55 players.

Oakland Banshees: The Oakland Banshees are a women's semi-professional American football team based in Oakland, California.  A member of the Independent Women's Football League, the Banshees play their home games at Chabot College in nearby Hayward.

Glens Falls Greenjackets: The Glens Falls Greenjackets are a semi-professional American football team in Glens Falls, NY.  The Greenjackets compete in the Empire Football League.  They were founded in 1928 as the Hudson Falls Greenjackets, making them the second oldest semi-pro team in the United States.  The oldest American semi-pro team, Watertown Red & Black (1896), also competes in the EFL.  Home games are played at East Field in Glens Falls, NY.  Preseason games are played at East Field and Putt LaMay Memorial Field (Glens Falls High School).

Los Angeles Amazons: The Los Angeles Amazons are a women's semi-professional American football team based in Los Angeles, California.  A member of the Women's Football Alliance, the Amazons play their home games at Miguel Contreras Learning Complex.

Detroit Dark Angels: The Detroit Dark Angels are a women's semi-professional American football team founded in 2010.  The Dark Angels are members of the Women's Football Alliance.  Based in the Detroit, Michigan area, the Dark Angels play their home games on the campus of John Glenn High School in nearby Westland.

J.P. Rooneys: The J.P. Rooneys (or formally the James P. Rooneys) were an independent semi-professional American football team, based in Pittsburgh, Pennsylvania.  The team was founded by Art Rooney, who is best known for being the founder of the Pittsburgh Steelers of the National Football League, and is considered to be unofficial beginnings of the modern-day Steelers.  The team played at Exposition Park and reportedly had up to 12,000 people in the stands at times.

Sacramento Sirens: The Sacramento Sirens are a women's semi-professional American football team, located in Sacramento, California.  The team has compiled one of the most successful records in women’s full tackle football.

Supporting paragraphs: J.P. Rooneys Art Rooney
Answer: The Chief