The land for Rienzi Playground was developed by the City of New York as a school and community play area. The portion to the northwest was acquired in three parcels between 1884 and 1914, and P.S. 21, the Philip H. Sheridan School, was erected during that time. Another small sliver of land was assigned to the Board of Education for a kindergarten playground. The large eastern portion of the park was acquired in 1941.
When the United States entered World War II with the attack at Pearl Harbor on December 7, 1941, construction of both school addition and playground was already underway. Half of the old two-story school building was demolished, and a three-story addition was erected by 1942. War-time shortages, however, probably delayed the construction of the new playground. Additional plans were prepared in 1943, and the park was completed along with eight other unfinished Work Projects Administration sites soon afterwards. It featured a comfort station, play equipment, wading pool, benches, and facilities for basketball, handball, and softball. In 1980 the partial reconstruction of the playground provided a handicapped-accessible drinking fountain and improved drainage, water supply, and electrical facilities.
In 1984 a spray shower replaced the original jungle gym, and new play equipment was erected where the original wading pool had been. A sandpit was removed to make way for a new play unit, and benches and paved areas were repaired as well.
The playground was formerly known as Sheridan Playground for the school's eponym, General Philip Henry Sheridan (1831-1888). Born in New York, Sheridan graduated from the United States Military Academy at West Point in 1853. When the Civil War broke out, he held a number of administrative posts before he was given command of the Second Michigan Cavalry in 1862. Victories at Booneville, Perryville, and other battles earned Sheridan a promotion to Major general.
When his troops were surprised by a counterattack at Cedar Creek in 1864, Sheridan mounted his horse Rienzi and made his famous twenty-mile ride to the battlefield to rally his men to victory. The celebrated horse was later renamed Winchester, stuffed, and acquired by the Smithsonian Institution. Rienzi the equine hailed from the hamlet of Rienzi, located in northeastern Mississippi. The town, in turn, probably took its name from Cola di Rienzi (1313?-1354), a Roman popular leader whose attempt to establish a democracy in Rome inspired an opera by Richard Wagner.
Sheridan's military career continued to rise as he cut off the Confederate retreat at Appomattox in 1864, forcing Confederate General Robert E. Lee's surrender to Union General Ulysses S. Grant. After the Civil War, Sheridan was appointed Lieutenant general in 1869, served with German armies in Europe during the Franco-Prussian War in 1870-71, and succeeded William T. Sherman as Commander-in-Chief of the United States Army in 1884. Sheridan died in 1888, the same year in which he was promoted to General.
In 1998 Council Member Lawrence A. Warden funded the $852,000 reconstruction of Rienzi Playground, which takes its name from Sheridan's trusty steed. The community garden which was to be placed next to the playground in turn inspired a famous children's story theme for the design. Steel fencing features ornaments that depict the adventures of Peter Cottontail, a character created by author A.A. Milne. A rabbit-shaped weathervane spins atop the reconstructed comfort station. The basketball court and handball courts were resurfaced, and the softball field asphalt was replaced with clay and sod. Rienzi Playground was also outfitted with two new play units, safety surfacing, and game tables, and two spray showers were renovated to complete the engaging atmosphere.