The 19th century in the United States refers to the period in the United States from 1801 through 1900 in the Gregorian calendar. For information on this period, see:

• History of the United States series:
  • History of the United States (1789–1849)
  • History of the United States (1849–1865)
  • History of the United States (1865–1918)
• Historical eras:
  • Jeffersonian era
  • Era of Good Feelings
  • Jacksonian era
  • American Civil War
  • Reconstruction era
  • Gilded Age
  • Progressive Era