What constitutional guarantees underlie the American free enterprise system?

A few of the freedoms and guarantees that safeguard the free enterprise system are the right to copyright and patent a new idea, protect individuals from the harmful acts of others, and ensure a national system of weights and measures to prevent anyone from being cheated.

In addition to this, within the 5th Amendment to the US Constitution, there is a right to maintain private property and to keep that property so long as there is no crime committed. If the government decides they need your private property for some reason, you must be reasonably compensated for it. They cannot simply take it away.