What phrase did the 1890 U.S. Census report use for the disappearance of a continuous American frontier line?

The 1890 U.S. Census report used the phrase “the closing of the frontier” for the disappearance of a continuous American frontier line.

The Census Bureau explained that unsettled territory had become so scattered that a frontier line could no longer be identified in its statistical maps. This did not mean that every western area was fully developed or that settlement had ended; it meant the earlier pattern of a moving boundary between settled and unsettled land had changed.

The announcement became a landmark in Wild West history. In 1893, historian Frederick Jackson Turner used the 1890 Census statement as the starting point for his influential “frontier thesis,” arguing that the frontier had strongly shaped American society and political culture.

A common mix-up is treating 1890 as the exact end of all western settlement. Native nations still faced federal policies and dispossession, while many western communities remained rural and sparsely populated. The phrase specifically described the statistical disappearance of a continuous frontier line.