Back to circa 1851, the Hudson River RR rail line ran on the west side streets north from Chambers St to Spuyten Duyvil.
Building of The Hudson River Railroad. http://www.catskillarchive.com/rrextra/abnyh.Html
"Commencing at the principal city station, at the junction of Chamber and Hudson streets, the track is laid through Hudson, Canal, and West streets, to Tenth avenue, which it follows to the upper city station, at Thirty-fourth street. Over this part of the route the rails are laid even with the streets, and the cars are drawn by what is called a "dumb engine." This is considered a great improvement over the use of horses, for drawing the cars through the streets, where, by the corporation regulations, locomotives are not allowed to run. This engine appears very much like an ordinary freight car. The machinery is entirely out of sight, and it is made to consume its own smoke. While passing through the city, it is preceded by a man on horseback, who gives notice of its approach by blowing a horn. At Thirty-fourth street, the line curves into Eleventh avenue, the dumb engine is detached, and the regular locomotive takes the train."
http://www.nytimes.com/2006/02/05/nyreg ... nted=print
"Below 30th Street, railroad cars drawn by horses funneled goods from the West Side railyards to Spring Street, with stops that today's subway riders will recognize: 23rd Street, 14th, Christopher.
In 1867, when the horses were replaced by steam engines, both traffic and speed increased. So did the inevitable conflicts arising from a street-level railroad operating in a crowded neighborhood. This lethal mix of industry and humanity earned Tenth Avenue the nickname Death Avenue.
"The traction of freight and passenger trains by ordinary locomotives in the surface of the streets is an evil which has already been endured too long," a state senator said in 1866, "and must be speedily abated."
The speedy abatement took half a century. Finally, a deadline was set: If the tracks were not raised above the street by May 1, 1908, the city would seize them. The date came and went, with neither elevation nor condemnation.
The only concession to safety that had ever been made was the recruitment of young men to ride horses one block in front of the trains, waving a red flag by day and a red light by night. These men, a total of 12 often recruited from the countryside, rode the two-mile stretch for more than 80 years starting in 1850.
A 1934 newsletter from a local apartment house wrote effusively about the West Side Cowboys, as the group was known. "The horses used in this unusual service are tried and true, and are perfectly aware of their important mission in life," the newsletter observes, noting that the horses "move surely and serenely," allowing their riders "to amuse the passerby with amazing variation of the routine waving the lanterns."
Apparently, citizens weren't impressed enough. They organized under the name The League to End Death Avenue, but nothing was done beyond the cowboys.
Five months after the 1908 deadline had passed, 7-year-old Seth Low Hascamp, dressed in a shirt and overalls, left his home at 544 West 44th Street and headed to school at St. Ambrose, on 54th Street. The train that killed him reportedly ripped his small body apart. Seth was one of hundreds who had died since the tracks had been laid. His family, neighbors and classmates held a silent funeral procession through the streets.
Another 20 years would pass before Mayor Jimmy Walker and Gov. Al Smith stepped in with public money to elevate the tracks. By 1933, 1,000 men had eliminated 105 street-level rail crossings, and when the elevated track was christened in June 1934, The New York Times reported, "The West Side is coming into its own."