The treaty, negotiated just days after Panama declared independence from Colombia with covert American backing, gave the United States rights 'in perpetuity' over a 10-mile-wide Canal Zone. The arrangement enabled construction of the Panama Canal, completed in 1914, but generated decades of Panamanian resentment over sovereignty that culminated in the treaties of 1977 returning the canal to Panama.
The circumstances behind the treaty were extraordinary even by the standards of American gunboat diplomacy: when Colombia's senate refused to ratify an earlier canal agreement, the Roosevelt administration quietly supported a Panamanian secession movement, then rushed warships to block Colombian troops from suppressing it.
Within two weeks of declaring independence, Panama's government—more accurately, a French engineer named Philippe Bunau-Varilla acting with dubious authority as Panama's minister—signed a treaty in Washington granting the U.S. far more territorial control than Colombia had ever offered, without a single Panamanian negotiator present in the room.
The Senate's ratification cleared the way for the canal's construction, one of the era's great engineering triumphs, but the treaty's one-sided terms festered as a symbol of American imperialism in Latin America for seven decades, fueling the nationalist movements that eventually forced Presidents Carter and Torrijos to negotiate the canal's return to Panamanian sovereignty in 1999.