The Internal Revenue Service (IRS) is the U.S. federal agency responsible for collecting taxes and administering the Internal Revenue Code, tracing its roots back to 1862, when President Abraham Lincoln and Congress created the Office of Commissioner of Internal Revenue to fund the Civil War with a temporary income tax. That emergency tax was later made permanent following the Sixteenth Amendment in 1913, and the agency was officially renamed the IRS in 1953. In fiscal year 2023, the IRS processed over 271 million tax returns and collected approximately $4.7 trillion, covering about 96% of the federal government's operational funding. The agency has faced criticism for politically targeted audits, disproportionate scrutiny of poor and minority taxpayers, and mishandling of COVID-19 stimulus payments, while also struggling with budget cuts, outdated technology, and a reduced workforce. Despite these challenges, research shows that IRS audits are highly effective, with a 2024 study finding that every $1 spent auditing high-income taxpayers yields over $12 in revenue, compared to only $5 for audits of below-median earners, highlighting the value of focused enforcement.