Located on marshy flatlands beside the Anacostia River, the gardens are composed of a series of irregularly sized and shaped ponds created by Walter Shaw. Within a larger 37-acre property purchased by Shaw in the late 1800s, there were eight acres of marsh that held an ice pond. Shaw purchased a dozen wild water lilies from his native Maine to add to the pond. As they flourished he began filling in more marshland, making additional ponds and planting new varieties of flowers. By the time he died in 1921, Shaw Gardens was a commercial enterprise run by his widowed daughter, Helen Shaw Fowler.
By 1930, the Anacostia River was so filled with silt that the Army Corps of Engineers was asked to dredge the river and use the silt to fill the wetlands. Fowler, along with the Kenilworth Citizens Association, fought for the preservation of the Shaw Gardens. Congress authorized their purchase in 1938, renaming them Kenilworth Aquatic Gardens adding the eight acres to Anacostia Park. No longer a commercial venture, the gardens are managed by the National Park Service. The property was listed in the National Register of Historic Places in 1978.