Third Avenue is a north-south thoroughfare on the East Side of the New York City borough of Manhattan, as well as in the center portion of the Bronx. Its southern end is at Astor Place and St. Mark's Place. It transitions into Cooper Square, and further south, the Bowery, Chatham Square, and Park Row. The Manhattan side ends at East 128th Street. Third Avenue is two-way from Cooper Square to 24th Street, but since July 17, 1960 has carried only northbound (uptown) traffic while in Manhattan above 24th Street; in the Bronx, it is again two-way. However, the Third Avenue Bridge carries vehicular traffic in the opposite direction, allowing only southbound vehicular traffic, rendering the avenue essentially non-continuous to motor vehicles between the boroughs. The street leaves Manhattan and continues into the Bronx across the Harlem River over the Third Avenue Bridge north of East 129th Street to East Fordham Road at Fordham Center, where it intersects with U.S. 1. It is one of the four streets that form The Hub, a site of both maximum traffic and architectural density, in the South Bronx. Like most urban streets, Third Avenue was unpaved until the late 19th century. In May 1861, according to a letter to the editor of The New York Times, the street was the scene of practice marching for the poorly equipped troops in the 7th New York Volunteer Infantry Regiment: "The men were not in uniform, but very poorly dressed, — in many cases with flip-flap shoes. The business-like air with which they marched rapidly through the deep mud of the Third-avenue was the more remarkable." Public transportation Buses Portions of Third Avenue are served by several routes in Manhattan. Buses serving Third Avenue include the Third and Lexington Avenues Line (or Third and Amsterdam Avenues Line). Note that southbound M98, M101, M102, and M103 service operates on Lexington Avenue north of East 24th Street. M98: between Hunter College and the Harlem River Drive M101 and M103: between Cooper Square and East 125th Street M102: between Cooper Square and East 116th Street Along the Bronx's Third Avenue also run several bus routes: Bx2: between East 138th Street to East 149th Street Bx15 (and formerly Bx55): between East 149th Street and Fordham Plaza Bx21: between East 138th Street and Boston Road Subway Third Avenue was the location of the Third Avenue Railroad, a horsecar line established in 1853