Panama Canal
Colombia, France, and later the United States controlled the territory surrounding the canal during construction. The US continued to control the canal and surrounding Panama Canal Zone until the 1977 Torrijos–Carter Treaties provided for handover to Panama. After a period of joint American–Panamanian control, in 1999, the canal was taken over by the Panamanian government. It is now managed and operated by the government-owned Panama Canal Authority.
Panama Canal
Another effort was made in 1843. According to the "New York Daily Tribune", August 24, 1843, a contract was entered into by Barings of London and the Republic of New Granada for the construction of a canal across the Isthmus of Darien (Isthmus of Panama). They referred to it as the Atlantic and Pacific Canal, and it was a wholly British endeavor. It was expected to be completed in five years, but the plan was never carried out. At nearly the same time, other ideas were floated, including a canal (and/or a railroad) across Mexico's Isthmus of Tehuantepec. Nothing came of that plan, either.