Mexico–United States border wall in the context of "San Diego"

Throughout U.S. history, the country experienced successive waves of immigration, particularly from Europe and later on from Asia and from Latin America. Colonial-era immigrants often repaid the cost of transoceanic transportation by becoming indentured servants where the employer paid the ship's captain. In the late 19th century, immigration from China and Japan was restricted. In the 1920s, restrictive immigration quotas were imposed but political refugees had special status. Numerical restrictions ended in 1965. In recent years, the largest numbers of immigrants to the United States have come from Asia and Central America (see Central American crisis).

Attitudes towards new immigrants have fluctuated from favorable to hostile since the 1790s. Recent debates have focused on the southern border (see Illegal immigration to the United States and Mexico–United States border wall) and the status of "dreamers", people who illegally migrated with their families when they were children and have lived in the U.S. for almost their entire lives (see Deferred Action for Childhood Arrivals).

Joe Biden's tenure as the 46th president of the United States began with his inauguration on January 20, 2021, and ended on January 20, 2025. Biden, member of the Democratic Party, had previously served as the 47th vice president from 2009 to 2017 under President Barack Obama, took office after defeating the Republican incumbent president Donald Trump in the 2020 presidential election. Upon his inauguration, he became the oldest president in American history, breaking the record set by Ronald Reagan. Alongside Biden's presidency, the Democratic Party also held their majorities in the House of Representatives and the Senate during the 117th U.S. Congress following the 2020 elections, thereby attained an overall federal government trifecta. Biden entered office amid the COVID-19 pandemic, an economic crisis, and increased political polarization.

Day one actions of his presidency included restoring U.S. participation in the Paris Agreement, revoking the permit for the Keystone XL pipeline and halting funding for the Mexico–United States border wall. On his second day, he issued a series of executive orders to reduce the impact of COVID-19, including invoking the Defense Production Act of 1950, and set an early goal of achieving one hundred million COVID-19 vaccinations in the United States in his first 100 days. The first major legislation signed into law by Biden was the American Rescue Plan Act of 2021, a $1.9 trillion stimulus bill that temporarily established expanded unemployment insurance and sent $1,400 stimulus checks to most Americans in response to continued economic pressure from COVID-19. He signed the bipartisan Infrastructure Investment and Jobs Act, a ten-year plan brokered by Biden alongside Democrats and Republicans in Congress to invest in American roads, bridges, public transit, ports and broadband access.