Was Duluth Ship Canal or Cross Florida Barge Canal cancelled for environmental reasons?
Duluth Ship Canal:  Begun privately in 1871, it was put under federal supervision and maintenance several years later. Cross Florida Barge Canal: The Cross Florida Barge Canal, now officially the Marjorie Harris Carr Cross Florida Greenway is a protected green belt corridor, one mile (1.6 km) wide in most places. Cross Florida Barge Canal:  It is named for the leader of opposition to the Cross Florida Barge Canal, a canal project to connect the Gulf of Mexico and the Atlantic Ocean across Florida for barge traffic. Cross Florida Barge Canal:  Two sections were built but the project was cancelled, mainly for environmental reasons.
Cross Florida Barge Canal