Short answers, pulled from the story.
The New York City draft riots erupted due to economic dependence on Southern cotton, racial tensions between white immigrants and Black workers, and resentment over the Enrollment Act which allowed wealthy men to pay for substitutes. The conflict intensified after the Emancipation Proclamation alarmed the white working class who feared job competition from freed slaves.
The New York City draft riots began on Monday July 13 when mobs attacked the assistant Ninth District provost marshal's office at Third Avenue and 47th Street. The violence continued through Thursday July 16 with a final confrontation occurring near Gramercy Park before the government resumed the draft on August 19 without further incident.
A mob of several thousand people including many women and children attacked the Colored Orphan Asylum around 4 pm on July 13 while it stood at 43rd Street and Fifth Avenue. Rioters looted the building of its food and supplies before police secured it long enough for orphans to escape as the institution burned down.
Historian James M. McPherson estimates that 119 or 120 individuals were killed during the New York City draft riots though other lists place the number as high as 1,200 dead. At least 2,000 people were injured according to reliable estimates from the period between July 13 and July 16.
Many black residents left Manhattan permanently with many moving to Brooklyn or New Jersey following the violence of the New York City draft riots. By 1865 the black population had fallen below 11,000 for the first time since 1820 as landlords drove black residents from their homes fearing mobs would destroy buildings.