(AP) - For hundreds of years, explorers and governments have dreamed of a waterway linking the Atlantic and Pacific. Proposed routes have ranged from Mexico to Colombia, but many have focused on Nicaragua. A few key moments:
_ 1524: Spanish conquistador Hernan Cortes writes that a canal across Central America would "be worth more than the conquest of Mexico."
_ 1825: The Republic of Central America asks U.S. help in building a canal across Nicaragua and signs a deal with a New York businessman. The project soon fails.
_ 1849 : Nicaragua gives Cornelius Vanderbilt's Accessory Transit Company the right to build a canal within 12 years. It builds a land transit route, but abandons it after years of local political turmoil.
_ 1872: U.S. government begins another survey of Nicaragua canal route.
_ 1881: French company starts construction on a rival route across Panama. It goes bankrupt in 1889.
_ 1885: Nicaragua again gives canal rights to the U.S., which sends surveyors to look at a possible route.
_ 1887: U.S. companies form to build a Nicaragua canal. They start construction, but project collapses in 1893.
_ 1897: U.S. President William McKinley appoints Nicaragua Canal Commission, which carries out a 20-month survey across the country and recommends a route.
_ 1904: U.S. begins construction on Panama Canal after buying French concession.
_ 1914: Panama Canal opens, giving ships an eight to 10 hour journey, 50 miles (80 kilometers) from Atlantic to Pacific. At the same time, the U.S. pays Nicaragua $3 million for an option to build and operate a canal there as well.
_ 1928: US Congress authorizes new survey of Nicaragua canal route. Survey continues into 1931.
_ 1989: Nicaragua government forms committee to study feasibility of a canal. Japanese experts come for consultations on the idea.
_ 1995: American, Asian and European investors plan 250-mile (400-kilometer), $1.4 billion high speed rail link _ a "dry canal." Nicaraguan President Arnoldo Aleman drops that plan two years later, citing likely negative environmental effects.
_ 1999: Aleman appoints a commission to study a maritime canal.
_ 2006: Nicaragua's government proposes a 173-mile (280-kilometer), $18 billion canal between points near Rivas on the Pacific and Bluefields on the Atlantic. Estimated to take 11-12 years to build and to eventually handle 4.5 percent of world shipping, with ships of up to 250,000 deadweight tons, about double those possible in the Panama Canal expansion that is scheduled to open in 2014.
_ 2008: Russian President Dmitry Medvedev floats idea of his country building the Nicaragua canal.
_ 2012: Nicaragua congress approves law for building a $30 billion canal. Two Dutch companies given contract to study its feasibility.
_ June 2013: Nicaragua's approves proposal for a $40 billion canal project to be built by a China-based consortium.
(Copyright 2013 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.)