Answer: Morocco

If you’re a U.S. history buff, you know treaties come and go, wars erupt and are quelled, and hardly a historical document big or small remains intact over time. That can’t be said for a peace treaty the U.S. signed with Morocco back in the 18th century. Morocco was the first country to formally recognize the United States as a sovereign nation (with a formal naval salute in 1777) and the two countries have been friends ever since.

In 1786, the United States and Morocco signed a peace treaty that has remained unbroken over the last two centuries and constitutes the longest running unbroken treaty the United States has ever entered into (though it was renegotiated in 1836). Morocco and the United States remain close to this day with numerous trade agreements between the two nations, military support, and joint efforts to introduce democracy into Northern Africa and the Middle East.