Immigration to the United States is a complex demographic phenomenon that has been a major source of population growth and cultural change throughout much of the history of the United States. The economic, social, and political aspects of immigration have caused controversy regarding ethnicity, economic benefits, jobs for non-immigrants, settlement patterns, impact on upward social mobility, crime, and voting behavior. In 2006 the United States accepted more legal immigrants as permanent residents than all other countries in the world combined. After ethnic quotas on immigration were removed in 1965 the number of actual (first-generation) immigrants living in the United States eventually quadrupled, from 9.6 million in 1970 to about 38 million in 2007. Over one million persons were naturalized as U.S. citizens in 2008. The leading countries of origin of immigrants to the United States were Mexico, India, the Philippines, and China. Nearly 14 million immigrants entered the United States from 2000 to 2010.

The United States of America (commonly abbreviated to the United States, the U.S., the USA, America, and the States) is a federal constitutional republic comprising fifty states and a federal district. The country is situated mostly in central North America, where its forty-eight contiguous states and Washington, D.C., the capital district, lie between the Pacific and Atlantic Oceans, bordered by Canada to the north and Mexico to the south. The state of Alaska is in the northwest of the continent, with Canada to the east and Russia to the west, across the Bering Strait. The state of Hawaii is an archipelago in the mid-Pacific. The country also possesses several territories in the Pacific and Caribbean.

At 3.79 million square miles (9.83 million km²) and with over 312 million people, the United States is the third or fourth largest country by total area, and the third largest by both land area and population. It is one of the world's most ethnically diverse and multicultural nations, the product of large-scale immigration from many countries. The U.S. economy is the world's largest national economy, with an estimated 2011 GDP of $15.1 trillion (22% of nominal global GDP and over 19% of global GDP at purchasing-power parity). Per capita income is the world's sixth-highest.

Joseph Robinette "Joe" Biden, Jr. (pronunciation: /ˈdʒoʊsɨf rɒbɨˈnɛt ˈbaɪdən/; born November 20, 1942) is the 47th and current Vice President of the United States, serving under President Barack Obama. A Democrat, he was a United States Senator from Delaware from January 3, 1973 until his resignation on January 15, 2009, following his election to the Vice Presidency.

Biden was born in Scranton, Pennsylvania and lived there for ten years before moving to Delaware. He became an attorney in 1969, and was elected to a county council in 1970. Biden was first elected to the Senate in 1972 and became the sixth-youngest senator in U.S. history. He was re-elected to the Senate six times, was the fourth most senior senator at the time of his resignation, and is the 15th-longest serving Senator in history. Biden was a long-time member and former chairman of the Foreign Relations Committee. His strong advocacy helped bring about U.S. military assistance and intervention during the Bosnian War. He opposed the Gulf War in 1991. He voted in favor of the Iraq War Resolution in 2002, but later proposed resolutions to alter U.S. strategy there. He has also served as chairman of the Senate Judiciary Committee, dealing with issues related to drug policy, crime prevention, and civil liberties, and led creation of the Violent Crime Control and Law Enforcement Act and Violence Against Women Act. He chaired the Judiciary Committee during the contentious U.S. Supreme Court nominations of Robert Bork and Clarence Thomas.