Constitution Annotated from the U.S. Congress
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.
This website offers analysis of what the Fourth Amendment means and the history of how it came into being enshrined in the U.S. Constitution.