In 1881, Grant moved to New York City and invested in a brokerage firm run by his son, Ulysses S. Grant Jr., and Ferdinand Ward. The firm went bankrupt in 1884, and Ward was incarcerated for illegal business practices. Left virtually penniless, and battling terminal cancer, Grant supported himself and his family through a cash advance on his autobiography.  He completed the memoirs shortly before his death on July 23, 1885.  Grant's body lay in state for three days before journeying in a six-mile-long funeral procession through New York City, where it was respectfully observed by an estimated 1 1/2 million mourners.  Harper's Weekly ranked Grant with Washington and Lincoln as "one of the three great heroes of the republic."

Grant's remains resided temporarily in a vault at Riverside Park.  In 1886, the city's Parks Department authorized a permanent gravesite and memorial in the park near 122nd Street.  Harper's Weekly approved of the selection as "a commanding site for the grave of the great commander."  In the most extensive fundraising campaign of its day, the Grant Monument Association collected $600,000 from 90,000 individuals and groups from all over the nation and around the world.

The Grant Association chose architect John Duncan to build his design for a neoclassical structure, featuring Doric columns, a 150-foot-tall domed rotunda, and bas relief of scenes from Grant's life.  The interior was to contain two sarcophagi, for Grant and his wife, while on the exterior was inscribed Grant's slogan from his 1868 presidential campaign:  "Let Us Have Peace."  Setbacks in its construction may have provoked the trivia question:  "Who's buried in Grant's Tomb?"  The answer was "no one" until its completion in 1897.  On the 75th anniversary of Grant's birth, April 27, 1897, over a million spectators on the specially-declared state holiday attended the parade and dedication service for the tomb, including Mrs. Grant and President William McKinley.