The 9th Ave. line was the world's first urban elevated train line , with a history dating back to the late 1860's When it then ran on Greenwich St. & the lower part of 9th ave. This line was gradually extended thru out Manhattan thru out the 1870's . In 1881 the Putnam RR from the Bronx side , came over to connect the line at 157th st & 8th ave. , giving the Manhattan Els it"s first link with the north american railroad web. The Putnam Bridge would later serve as the springboard for the extension of 6th & 9th ave. el service into the Bronx , in the late 1910's. where as the Putnam RR line was disconnected from the bridge. Service on the 9th Ave. EL south of the 155th st sta. was abandon on June 11th 1940. The last portion from 155th st to the Jerome Avenue line was used as a shuttle till 1958.