Construction of the Third Avenue El, opened from 1878 in sections, followed by the Second Avenue El, opened in 1879, linked the Upper East Side's middle class and skilled artisans closely to the heart of the city, and confirmed the modest nature of the area to their east.
The ghostly "Hamilton Square", which had appeared as one of the few genteel interruptions of the grid plan on city maps since the Commissioners' Plan of 1811, was intended to straddle what had now become the Harlem Railroad right-of-way between 66th and 69th Streets; it never materialized, though during the Panic of 1857 its unleveled ground was the scene of an open-air mass meeting called in July to agitate for the secession of the city and its neighboring counties from New York State, and the city divided its acreage into house lots and sold them.
From the 1880s the neighborhood of Yorkville became a suburb of middle class Germans.

Gracie Mansion, the last remaining suburban villa overlooking the East River at Carl Schurz Park, became the home of New York's mayor in 1942.
The East River Drive, designed by Robert Moses, was extended south from the first section, from 125th Street to 92nd Street, which was completed in 1934 as a boulevard, an arterial highway running at street level; reconstruction designs from 1948 to 1966 converted FDR Drive, as it was renamed after Franklin Delano Roosevelt, into the full limited-access parkway that is in use today.

Demolishing the elevated railways on Third and Second Avenues opened these tenement-lined streets to the construction of high-rise apartment blocks starting in the 1950s.
However, it had an adverse effect on transportation, because the IRT Lexington Avenue Line was now the only subway line in the area.
The construction of the Second Avenue Subway was originally proposed in 1919.
Finally, on January 1, 2017, the first phase of the line was completed with three new stations opened.
This brought in new local business to the area and had positive impact on real estate prices in the Upper East Side.
Construction of the Third Avenue El, opened from 1878 in sections, followed by the Second Avenue El, opened in 1879, linked the Upper East Side's middle class and skilled artisans closely to the heart of the city, and confirmed the modest nature of the area to their east. The ghostly "Hamilton Square", which had appeared as one of the few genteel interruptions of the grid plan on city maps since the Commissioners' Plan of 1811, was intended to straddle what had now become the Harlem Railroad right-of-way between 66th and 69th Streets; it never materialized, though during the Panic of 1857 its unleveled ground was the scene of an open-air mass meeting called in July to agitate for the secession of the city and its neighboring counties from New York State, and the city divided its acreage into house lots and sold them. From the 1880s the neighborhood of Yorkville became a suburb of middle class Germans.
Gracie Mansion, the last remaining suburban villa overlooking the East River at Carl Schurz Park, became the home of New York's mayor in 1942. The East River Drive, designed by Robert Moses, was extended south from the first section, from 125th Street to 92nd Street, which was completed in 1934 as a boulevard, an arterial highway running at street level; reconstruction designs from 1948 to 1966 converted FDR Drive, as it was renamed after Franklin Delano Roosevelt, into the full limited-access parkway that is in use today.
Demolishing the elevated railways on Third and Second Avenues opened these tenement-lined streets to the construction of high-rise apartment blocks starting in the 1950s. However, it had an adverse effect on transportation, because the IRT Lexington Avenue Line was now the only subway line in the area. The construction of the Second Avenue Subway was originally proposed in 1919. Finally, on January 1, 2017, the first phase of the line was completed with three new stations opened. This brought in new local business to the area and had positive impact on real estate prices in the Upper East Side.
Upper East Side