Grant and sherman decided on a plan of action to end the war after the battle of

petersburg

vicksburg

gettysburg

sharpsburg

The correct answer for the question that is being presented above is this one: "Vicksburg." Grant and Sherman decided on a plan of action to end the war after the Battle of Vicksburg. The Battle of Vicksburg was the culmination of a long land and naval campaign by Union forces to capture a key strategic position during the American Civil War.