Answer:
The answer to this question is 1861 to 1865
Step-by-step explanation:
The war started in April 12, 1861, on south carolina, when the Confederates bombarded Union soldiers at Fort Sumter, The war ended in the Spring.
On April 9 1865, Robert E. Lee yielded to the last major Confederate army to Ulysses S. Grant at Appomattox Courthouse.
The number that represents the time period that led to the civil war is April 12, 1861 - April 9 1865.