The financial acronym IRS stands for the Internal Revenue Service, the principal collector of tax revenue for the United States federal government. The IRS is a Department of the Treasury bureau and is directed by the Commissioner of Internal Revenue.
For example, the IRS has the responsibility of collecting taxes and also of the interpretation and enforcement of the Internal Revenue Code which makes up the federal tax law in the United States. The government entity was begun when Abraham Lincoln created the office of the Commissioner of Internal Revenue in 1862, whereupon the Revenue Act of 1862 was passed to pay for expenses for the Civil War. The IRS has gone through many changes since then. For example, in 2006 the IRS began outsourcing the collection of taxpayer debt to private collection agencies. The agency stopped this practice in 2009 to save money by doing the collection work in-house.