Grant's greatest contributions to the Union war effort came after Lincoln placed him in charge of the Army of the Potomac. The military head of the war effort always was the appointed commander of this Army.
Both Grant and General Sherman carried on the War with the same philosophy as their Commander in Chief, President Abraham Lincoln. All three of these men wanted to end the war as soon as possible. It is believed that this objective would accomplish two vital goals:
A. End the bloodshed as soon as possible; and
B. Bring the Confederacy back into the Union.
Some people have criticized the methods used by Grant & Sherman which was conducting relentless war.
This resulted in mass destruction and caused many deaths and destroyed property. It also caused terror, as if terror was anything new to a war. The problem was that this relentless war was against other Americans. The strategy succeeded.
I do not believe these Generals or Lincoln were cruel men. They did not relish the war they had to conduct. It was unfortunate that this had to happen. There are solid arguments against their policies.
But, yes their impact shaped the course of the War. That being it shortened the war and thus saved more lives then if the War had continued another 2 -3 years which was a possibility. This is one opinion of their impact. There certainly are others.
The two Union officers who believed in and demonstrated the effectiveness of the strategy of total war were General Ulysses Grant and General William Sherman. Grant's Overland Campaign in 1864 and Sherman;s March to The Sea in 1864 were examples of total war by two military leaders.
General Lee surrendered at appomattox
Became General-in-Chief of the U.S. Army when Grant retired in order to become President.
The two victorious Generals were U.S. Grant and W.T. Sherman.
Grant, Sherman, Sheridan, Meade, Hooker, Burnside are the best known. There were many generals since various state militias would elect a general.
To change the course of the war. Grant and Sherman both believed that it was the strength of the people's will that was keeping the war going.
Wonderful question! Tacticaly Grant because he changed the way the War Between the States was fought, but strategicaly Sherman because he changed the way future wars were fought. The nod goes to Sherman.
For a major part of the US Civil War, General Sherman reported to General US Grant. They did not always agree on tactics. For example, Sherman thought it was foolish of Grant to order him to dig a canal to change the course of the Mississippi River in order to capture Vicksburg. Also, Sherman believed that Grant was over worried about news reporters in their camps.
Grant and Sherman
Grant to Sherman: "Make Georgia howl!"
Sherman carried credibility with Grant, tested under fire, and was a trusted friend.
Scorched earth.
During the US Civil War, Union generals Grant and Sherman employed what was called total war and /or scorched earth tactics.
Grant was willing to fight hard enough to end the war. Sherman instituted the tactic of destroying an enemy's infrastructure and ability to wage war. Example: Sherman's march to the sea through Atlanta, GA.
Sherman practiced a strategy called total war. They both surrounded their opponents.
William Tecumseh Sherman and Ulysses S. Grant
Grant. Sherman. Sheridan.