For more than 200 years, the Battery, located at the southern tip of Manhattan Island, has been a critical part of New York City’s history. Originally built in 1812 as part of the harbor’s defenses, the fortification was later adapted for other uses. In 1855, Castle Clinton, at the time known as Castle Garden, opened its doors as the first immigration processing center in the United States. During its role as an immigration center, Castle Garden welcomed over 8 million people through its doors. One in six native-born American citizens can trace their lineage back to Castle Garden.

On April 18, 1890 Castle Garden closed its doors as an immigration center in preparation for the opening of Ellis Island. New York City repurposed the historic building and transformed it into an aquarium. The New York City Aquarium opened on December 10, 1896, and its exotic fishes and Beluga whale made the aquarium one of the city's most popular attractions. The New York City Aquarium was relocated to Coney Island in 1941.

If you walk around the park, you’ll encounter many monuments and a few other structures. At the north West edge you’ll reach Pier A. Pier A was built from 1884 to 1886 to serve the New York City Department of Docks and Harbor Police. The pier was expanded in 1900, and again in 1919, with a clock installed in the pier's tower as a memorial to 116,000 US servicemen who died during World War I.

The clock was unveiled at noon on January 25, 1919, and it is said to be the first World War I memorial erected in the United States.

Passing Castle Clinton as we walk towards the East River waterfront, we can see its current role as a National Monument. The structure was saved from demolition in 1946, and opened in 1975 after an extensive restoration.

If you continue walking along the waterfront, facing Brooklyn, you'll pass a few ferry's docking and buildings. The ferry's history of rise, fall, and rise again is typical of New York City’s infrastructure and transportation. In 1905, the City of New York began a “progressive takeover of the ferry system” when it acquired the ferry route running between Whitehall Street (Manhattan) and Saint George (Staten Island) from the Staten Island Rapid Transit.

By 1925, the New York City municipal ferry system had reached its pinnacle as it operated over a dozen routes that provided ferry service to all five boroughs and New Jersey. Twenty years later, only one municipally-operated ferry route remained, the same route that it started with in 1905, what today we call the Staten Island Ferry.

In the original design, the Municipal Ferry Terminal had two buildings, one with two slips going between Whitehall-Saint George (opened in 1906), and the other for the 39th Street Ferry that went to South Brooklyn (opened in 1909). It is now called the Battery Maritime Building and was listed on the National Register of Historic Places in 1976.

Moving along South Street, you’ll see on the Manhattan side a small trapezoidal square. This is the old Coenties Slip, once a berth for sailing vessels. The slip was filled with land in 1835 to become a street. Coenties Slip was named for Conraet Ten Eyck and his wife, Antje, a moneyed Dutch couple who lived in the area in the 1600s. (“Coenties,” most historians agree, is a contraction of Conraet and Antje.)

In 1884 the small square created by filling in Coenties Slip was named Jeannette Park in honor of Jeannette, the flagship of the ill-fated Arctic Expedition (1879-1881) sponsored by New York Herald editor James Gordon Bennett, Jr., who named the ship after his sister. Today Coenties Slip is known as Vietnam Veterans Plaza and it is a triangular shaped park.

In the late 19th century and early 20th century tugboats, canal boats, and a steam lighter would have tied together and to the end of piers along the East River, ready to chug off with a barge or stand downriver to pick up a sailing ship and tow her into South Street.

Lower Manhattan and the Seaport was an international center of commerce by the mid-19th century, and many slips were filled with land further into the East River in several construction episodes. At the southern edge of the South Street Seaport Historic District, you’ll reach Burling Slip. Many of the buildings currently standing along this slip, including those now housing the Seaport Museum, were built looking out onto the open water of Burling Slip, where merchant ships docked to load and unload cargo.

The portion of Burling Slip, that is now the site of Imagination Playground, functioned as a docking basin during the first half of the nineteenth century.

The Port of New York in 1860, centered on South Street, was visited by more than 4,000 ships annually. In 1895 New York was only a few years away from overtaking London as the world’s busiest port. It was through the Seaport at South Street, and the multitude of ships that once docked here, that New York achieved global significance.

It was on South Street, “the Street of Ships,” where New York’s transformation into a global metropolis began. At the turn of the last century, many people came down to South Street to watch the ships and schooners along Pier 17 and the Market slip.

The flagship of the Seaport Museum’s fleet of historic ships, the British- built full-rigged Wavertree, is one of the last remaining examples of the bulk cargo sailing ships that connected New York to all the major ports of the world. Today her masts rise alongside the city’s skyscrapers, but in 1895, when Wavertree first arrived in New York, there was a forest of masts rising over South Street.