The Internal Revenue Service (IRS) is the revenue service of the United States federal government. The agency is a bureau of the Department of the Treasury, and is under the immediate direction of the Commissioner of Internal Revenue. The IRS is responsible for collecting taxes and the interpretation and enforcement of the Internal Revenue Code.

The IRS has its headquarters in Washington, D.C., and does most of its computer programming in Maryland. It currently operates five service centers around the country (in Austin, TX; Cincinnati, OH; Fresno, CA; Kansas City, MO; and Ogden, UT), at which returns sent by mail are received. These centers do the actual tax processing; different types of returns are processed at the various centers (with some centers processing individual returns and others processing business returns). The IRS also operates three computer centers around the country (in Detroit, Michigan; Martinsburg, West Virginia; and Memphis, Tennessee).

In July 1863, during the Civil War, President Abraham Lincoln and Congress created the office of Commissioner of Internal Revenue and enacted a temporary income tax to pay war expenses (see Revenue Act of 1862). The position of Commissioner exists today as the head of the Internal Revenue Service.

Harold Watson "Trey" Gowdy III (born August 22, 1964) is the U.S. Representative for South Carolina's 4th congressional district. He is a member of the Republican Party. Before his election to Congress, he was the solicitor (district attorney) for the state's Seventh Judicial Circuit, comprising Spartanburg and Cherokee counties.

He was born in 1964 in Greenville, South Carolina, the son of Novalene (née Evans) and Dr. Harold Watson "Hal" Gowdy, Jr. Trey graduated from Spartanburg High School in 1982. He earned a B.A. in history from Baylor University in 1986 and a law degree from the University of South Carolina School of Law in 1989.

Following law school, he clerked for the late John P. Gardner on the South Carolina Court of Appeals and United States District Court Judge Ross Anderson. He then went into private practice before becoming a federal prosecutor in April 1994. He was awarded the Postal Inspector’s Award for the successful prosecution of J. Mark Allen, one of “America’s Most Wanted” suspects.

Elijah Eugene Cummings (born January 18, 1951) is the U.S. Representative for Maryland's 7th congressional district, serving since 1996. He is a member of the Democratic Party. The district includes just over half of Baltimore City, as well as most of Howard County. He previously served in the Maryland House of Delegates.

Cummings was born in Baltimore, the son of Ruth and Robert Cummings. He graduated with honors from Baltimore City College in 1969. He later attended Howard University in Washington, D.C., where he served in student government as sophomore class president, Student Government treasurer and later Student Government President. He became a member of the Phi Beta Kappa Society and graduated in 1973 with a Bachelor of Arts in Political Science.

Cummings attended law school at the University of Maryland, Baltimore, graduating in 1976 and entering the Maryland Bar in December 1976. He practiced law for 19 years before first being elected to the House in the 1996 elections.

For 16 years, Cummings served in the Maryland House of Delegates. In the Maryland General Assembly, he served as Chairman of the Legislative Black Caucus of Maryland and was the first African American in Maryland history to be named Speaker pro Tempore, the second highest position in the House of Delegates.

Darrell Edward Issa (/ˈaɪsə/; Arabic: عيسى‎; born November 1, 1953) is the U.S. Representative for California's 49th congressional district, serving since 2001. He is a member of the Republican Party. He was formerly a CEO of Directed Electronics, the Vista, California-based manufacturer of automobile security and convenience products. His district consists of portions of southern Riverside County and northern San Diego County. The district was numbered as the 48th District during his first term and was renumbered the 49th after the 2000 Census. Since January 2011, he has served as Chairman of the House Oversight and Government Reform Committee.

Issa is a self-made millionaire with a net worth estimated between $220 and $448 million, making him one of the wealthiest members of Congress. He was a major contributor to the 2003 recall election of Governor Gray Davis.

Issa was born in Cleveland, Ohio, the second of six children. His mother was a Mormon and his father Eastern Orthodox. Issa is the grandson of Lebanese immigrants.

Rafael Edward Cruz, known as Ted Cruz (born December 22, 1970), is the former Solicitor General of the U.S. state of Texas, a position which he held from 2003 to May 2008. Cruz was appointed by Texas Attorney General Greg Abbott. He was the first Hispanic Solicitor General in Texas, the youngest Solicitor General in the United States, and had the longest tenure in the post thus far in Texas history. He is currently a partner at the law firm Morgan, Lewis & Bockius, where he leads the firm’s U.S. Supreme Court and national appellate litigation practice.

Cruz is a candidate for the 2012 Republican nomination for the United States Senate seat being vacated by Kay Bailey Hutchison.

Cruz previously served as the director of the Office of Policy Planning at the Federal Trade Commission, an Associate Deputy Attorney General at the United States Department of Justice, and as Domestic Policy Advisor to U.S. President George W. Bush on the 2000 Bush-Cheney campaign. In addition, from 2004-2009 Cruz was an Adjunct Professor of Law at the University of Texas School of Law in Austin, where he taught U.S. Supreme Court litigation.