The African American Day Parade literature states that it is the largest black parade in America. The parade is held up Adam Clayton Powell, Jr. Boulevard (Seventh Avenue), from 111 Street to 142 Street, in September.

http://www.nyc.gov/html/nycmg/nyctv/html/shows/paradetown.shtml
Episode 2: African American Day, Part 1
Join NYC TV in celebrating African American heritage — expressed through music, dance, food, and other special events — as we present highlights from this year's annual African American Day Parade in Harlem. Community leaders and performers marched down Adam Clayton Powell Boulevard in a demonstration of unity and culture that you will not want to miss!

Episode 3: African American Day, Part 2
NYC TV continues its coverage of the African American Day parade. Part 2 brings you more of this unique parade, highlighting one of New York City's oldest and most culturally diverse communities.

http://www.nytimes.com/2005/09/16/arts/16spar.html?pagewanted=print
AFRICAN-AMERICAN DAY PARADE, Adam Clayton Powell Jr. Boulevard, from 111th to 142nd Streets, Harlem. Sunday at 2 p.m.

http://www.nycvisit.com/content/index.cfm?pagePkey=1124&CFID=7673341&CFTOKEN=93604313
There are two fantastic parades September: the West Indian-American Day Parade (718/467-1797, http://www.wiadca.com) draws 3.5 million spectators to New York's Caribbean Carnival/Mardi Gras, the largest such event in the U.S.; and the African-American Day Parade, the largest Black parade in America, features marching bands and floats.