Warrantless searches in the United States

Warrantless searches are searches and seizures conducted without search warrants.

In the United States, warrantless searches are restricted under the Fourth Amendment to the United States Constitution, part of the Bill of Rights, which provides that, "The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized."

In the Thirteen Colonies, agents of the British Empire utilized general warrants to authorize searches in the homes of colonists – such warrants allowed any place to be searched for any thing at any time, all at the whim of the holder. They were viewed as abuses of power, contributing to increased tensions that ultimately led to the American Revolution. The Fourth Amendment barred all warrantless searches and all general warrants; nevertheless, the interpretation and limitations of the Fourth Amendment and the permissibility of warrantless searches under certain circumstances (such as wartime) have been important in the history of executive and judicial power in the United States.

During the American Revolutionary War, "the Continental Congress regularly received quantities of intercepted British and Tory mail". See intelligence in the American Revolutionary War.

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