The Office of the Commissioner of Internal Revenue was established by act of July 1, 1862 (26 U.S.C. 7802). The Internal Revenue Service (IRS) is responsible for administering and enforcing the internal revenue laws and related statutes, except those relating to alcohol, tobacco, firearms, and explosives. Its mission is to collect the proper amount of tax revenue, at the least cost to the public, by efficiently applying the tax law with integrity and fairness.