Based on the post war writings of Confederate General PTBeauregard, artillery played a major role in the Battle of Shiloh.It was vital that the Confederates create a Union surrender on thefirst day of the battle. If this had been the case, the nigh timearrival of Union General Don Carlos Buell and his 20,000 troopreinforcements would have caused Buell to retreat. As it happened,Beauregard wrote that the ability of the Union's artillery late onApril 6, 1862 was the reason that the Federals under US Grant wereable to avoid defeat. The Union's artillery batteries numbering 20cannon provided an effective defense that prevented Beauregard toforce a Union surrender.