The treaty became effective on November 30, 1977; 17 days later 232 American prisoners had been verified and returned to the U.S., and were either released or serving the balance of their sentences. Within a 6-month span hearings on the treaty had been held by the Senate Foreign Relations Committee and a subcommittee of the Senate Judiciary Committee, the Senate ratified the treaty, and implementing legislation already drafted was passed into law by Congress, signed by the President, and put into operation by Executive Branch. The Department of Justice sent teams to Mexico to interview all prospective transferees and provided attorneys for verifying hearings. The Bureau of Prisons computed credits for time spent by transferees in Mexican prisons and arranged for their dispersal to U.S. prisons. The Judicial Branch made arrangements for U.S. magistrates to act as verifying officials in Mexico, and counsel was made available for each of the transferees. The Probation System conducted background investigations to expedite parole hearings for the returning prisoners. Beyond these accomplishments, the treaty signifies the first time in international history prisoners convicted of civil crimes in a nation other than their own have been transferred to their home nation to serve the sentence imposed by the civil law of the foreign country. For the first time in U.S. history, U.S. judicial officers carried out assignments under terms of an international treaty in a foreign land. And finally, the treaty has been heralded by other countries as a significant step forward in international agreements, and many nations are watching the program to discover whether to initiate such agreements themselves. Canada has already entered into a similar treaty with the U.S. (Author abstract modified)