What if confederates took Rye , Ossining , Nyack, Coney Island but lost Harrison. Union still hold new york .

If the Confederates were able to capture Rye, Ossining, Nyack, and Coney Island but lost Harrison, it would have been a significant blow to the Union's efforts to control New York City. These locations are all within close proximity to the city and would have allowed the Confederates to establish a strong foothold in the area.

However, the loss of Harrison would have been a setback for the Confederates, as it is a key transportation hub for the region. Without control of Harrison, the Confederates would have had a more difficult time moving troops and supplies to the front lines.

Overall, the Union's hold on New York City would have been threatened, but not necessarily lost. They would have had to re-evaluate their strategy and reinforce their defenses to prevent further Confederate advances. It is impossible to say how the rest of the war would have played out in this scenario, but it would have certainly changed the course of history.