The East Coast Greenway Alliance (ECGA) has already completed almost a third of the 3,000-mile-long path, which would ultimately connect 15 states. The ECGA uses its resources to fund and organize local groups and volunteers to build sections of the path. The Durham, North Carolina-based organization has highlighted that this approach fosters a feeling of community ownership of the path while taking advantage of local knowledge in planning and executing its construction.
The growth of the path can be piecemeal, but 834 miles are already in place, and the ECGA hopes to add another 200 miles in the next 4 years. When complete, the path will run from Calais, Maine to Key West, Florida, and could be used by locals or serious cross-country travelers alike.
More details on the ECGA can be found here.