The island is between the Washington Channel and the Potomac River, and on it the park lies southeast of the Jefferson Memorial and the 14th Street Bridge.

The DC Circulator's National Mall Route, which began service in June 2015, provides the best public transportation option for reaching East Potomac Park.

Exposed to the air about half the time, the sewage began decomposing, creating a powerful, rank smell.

[7][8][9] Much of the dredged material was used to build up the existing tidal flats in the Potomac River as well as sandbars which had been created by silting around Long Bridge.

[13] Over the next two decades, most of East Potomac Park lay untouched, and dense thickets of trees and brush grew up on the island.

[7] The McMillan Plan called for turning the undeveloped land into a formal park with extensive recreation facilities.

[20] A portion of the park then served in 1910 as a nursery for providing trees, shrubs, and flowers for Congress, the White House, and other governmental agencies.

[33] Congress transferred jurisdiction of East Potomac Park to the District of Columbia from the federal government in legislation enacted on August 1, 1914.

[33] The first three of the park's many baseball diamonds were established in early 1915,[44] and extensive cinder-lined walking paths constructed in summer 1915 and spring 1916.

[33] The Corps proceeded to clear grade, plow, and seed 88 acres (360,000 m2) of land in the center of the park for use as athletic fields in the summer of 1916 and again in the spring of 1917.

[45] No funding for the fieldhouse was provided, but the following year the Corps of Engineers, acting on a request from local sportsmen, won approval for construction of a golf course on the lower two-thirds of the park.

[46] Work on the course was delayed for a variety of reasons, but construction finally began in January 1917, when golf course architect Walter Travis visited the city to see the site and begin designing the course.

[47] Although funding for construction was approved in May 1918, work was delayed during World War I as temporary soldiers' barracks were built in and victory gardens were extensively planted throughout East Potomac Park.

The first was the headquarters of the NPS' National Capital Region (NCR), constructed in the northern part of the park near the south shoreline and completed in 1963.

[60][d] In 1969, a one-story addition containing a cafeteria and training center was added to the north end of the NCR headquarters structure.

[65] In 2015, the National Park Service proposed a major restructuring of all federal government operations in the Mission 66 buildings.

A portion of the USSP District 1 access road and grounds were in a floodplain expected to have a severe flood every 10 to 25 years.

Additionally, planners noted that the USPP District 1 headquarters was not configured to meet heightened security needs in a post-9/11 world.

[41] NPS and USPP officials said they anticipated upgrading the HVAC and mechanical systems of the NCR headquarters, making the structure Americans with Disabilities Act compliant, and renovating the interior to create an open workspace from closed offices, which would allow far more efficient use of space and the demolition of some temporary office trailers currently on the northern corner of the complex's parking lot.

A new 13,000-square-foot (1,200 m2) USPP District 1 station would be constructed on the site of the temporary trailers, allowing the fieldhouse to be returned to public use.

[65] Beginning in 1971, the United States lightship Chesapeake was anchored off East Potomac Park in the Washington Channel.

The construction bypassed normal review procedures for the use of public land and design of building in the National Capital Area, although members (but not staff) of the United States Commission of Fine Arts and the National Capital Planning Commission were later briefed about the project and sworn to secrecy.

The 5-mile (8.0 km) long riprap seawall was disintegrating, sidewalks throughout the park were often cracked and buckled, and the miniature golf course was worn and dirty.