What is the most prominent advantage Grant had against Lee?

The most prominent advantage Ulysses S. Grant had against Robert E. Lee during the Civil War was his ability to leverage superior manpower and resources. The Union had a larger population and better access to industrial capabilities, allowing Grant to replenish his forces more effectively after battles. Additionally, Grant's strategic focus on continuous engagement and attrition wore down Lee's Army of Northern Virginia, which struggled with supply shortages and troop depletion. This relentless pressure ultimately contributed to the Union's victory.