The 15 miles was the shift change for horses or mules.
10 Feb 2013
From 1829 to about 1905, residents of the Long Homestead would be witness to unique sights and sounds of Erie Canal boatmen, horses, and mules. Canal boats sometimes moored (tied up) for months during winter, right in front of the Long Homestead, waiting for the start of the canal shipping season. When you visit, note that the green-painted steel girder pedestrian bridge, just to the west of the Long Homestead, across Tonawanda Creek, is on the site of a former Erie Canal towpath bridge.
However, by the 1890s, railroads had taken away all of the canal's passenger business and most of its cargo business. So, by 1900, a new larger canal, the Erie Barge Canal, was being planned. Construction began in 1905 and was completed in 1918. By utilizing “canalized” natural waterways, the new canal would be much larger, faster and better able to compete with the railroads. The Erie Barge Canal would be the first canal to use motorized vessels, thereby eliminating the mules, horses and towpaths. The number of locks would also be reduced from 83 to only 35, which helped speed up freight delivery.