In early September 2025, President Donald Trump announced that he would deploy federal troops into several major U.S. cities to quell unrest — even if governors objected.

The announcement immediately set off a wave of debate. Critics pointed to the Posse Comitatus Act of 1878, a law meant to prevent the use of the Army as a domestic police force. Supporters countered with the Insurrection Act of 1807, a much older law that presidents have invoked many times to justify troop deployments at home.

So here’s the central question for us today: Is Trump doing something unprecedented — or is he following a long, if uneasy, American tradition of presidents sending troops into the streets?

Host: Alan
Research: Elena, the Roots of Today Archivist

Music: Andrii Poradovskyi (lNPLUSMUSIC – Pixabay)

Sources:

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Further Reading:
Finkelman, Paul, ed. Encyclopedia of American Civil Liberties. New York: Routledge, 2006.
Includes a clear entry on the Posse Comitatus Act and its legal/political background.

Fisher, Louis. Military Tribunals and Presidential Power. Lawrence: University Press of Kansas, 2005.
Readable treatment of civil-military boundaries and presidential authority, with good context for how the Insurrection Act has been invoked.

Banks, William C. Soldiers on the Home Front: The Domestic Role of the American Military. Cambridge, MA: Harvard University Press, 2016.
Written in a narrative style, this book bridges history and law, explaining the practical consequences of using the military for domestic purposes.