Incumbents
- President: William McKinley (Republican)
- Vice President: Garret Hobart (Republican) (until November 21), vacant (starting November 21)
- Chief Justice: Melville Fuller
- Speaker of the House of Representatives: Thomas Brackett Reed (R-Maine) (until March 4), David B. Henderson (R-Iowa) (starting December 4)
- Congress: 55th (until March 4), 56th (starting March 4)
Read more about this topic: 1899 In The United States