A combined land and naval assault on Plattsburgh, a town on the shores of Lake Champlain, was beaten off by the American defenders,the British forces retreating back into Canada.
If you mean, "not end the war," Lee's army retained retained its cohesion and command structure, and, once back in Virginia, regained its morale. Had Meade vigorously pursed Lee on July 4th, that...
The Union Monitor and the Confederate Merrimack, renamed the Virginia, traded blows in Hampton Roads for several hours but neither was able to disable the other. Eventually both ships retreated to...