The Meigs Elevated Railway was an experimental steam-powered monorail invented by Josiah V. Meigs (also known as Joe Vincent Meigs)[1] of Lowell, Massachusetts.
A 227-foot demonstration line was built in 1886 in East Cambridge, Massachusetts on land abutting Bridge Street, now Monsignor O’Brien Highway. Never expanded, it ran until 1894 (source Wikipedia)
The following pictures come from Retronaut.
Michael Bradley - Time Traveler 