Why was Ulysses S. Grant elected president in 1868 and 1872?

The United States presidential election of 1868 was the 21st quadrennial presidential election, held on Tuesday, November 3, 1868. In the first election of the Reconstruction Era, Republican nominee Ulysses S. Grantdefeated Democrat Horatio Seymour. It was the first presidential election to take place after the conclusion of the American Civil Warand the nationwide abolition of slavery.