American Fur Company v. United States (1829)
In American Fur Company v. United States (1829) 27 U.S. 358, the Court recognized the Act of May 6, 1822, c. 58, 3 Stat. 682, authorizing Indian agents to cause the goods of traders in the Indian Country to be searched upon suspicion or information that ardent spirits were being introduced into the Indian Country, to be seized and forfeited if found.
Mr. Justice Washington, speaking for the court, said that "where two or more persons are associated together for the same illegal purpose, any act or declaration of one of the parties, in reference to the common object, and forming a part of the res gest?, may be given in evidence against the others."
The Supreme Court said: "whatever an agent does or says, in reference to the business in which he is at the time employed, and within the scope of his authority, is done or said by the principal; and may be proved, as well in a criminal as a civil case; in like manner as if the evidence applied personally to the principal."