Benjamin Prentiss

Benjamin Mayberry Prentiss (November 23, 1819 – February 8, 1901) was an American soldier and politician. He fought in the Mexican–American War and on the Union side of the American Civil War, rising to the rank of major general. He commanded a division at the Battle of Shiloh, which suffered heavy casualties while defending what became known as the Hornet's Nest from continued Confederate assaults, and he eventually surrendered his division. He was criticized by some for his conduct in that battle. After his exchange, he continued to serve in the army until his resignation in 1863. He spent much of his remaining life practising as a lawyer and as a politician in the Republican Party.

In the battle of Shiloh (April 6-7, 1862), Prentiss took full command of the position after Wallace was fatally wounded and eventually surrendered the Hornet's Nest along with 2,200 other Union soldiers. He surrendered his sword to Lt. Colonel Francis Marion Walker of the 19th Tennessee Infantry. After the battle he was considered a hero, having held off the Confederate States Army long enough to allow General Grant to organize a counterattack and win the battle. Grant later played down Prentiss's role in the victory, possibly because of mutual dislike between the two generals.

After being released as part of a prisoner exchange in October the same year, Prentiss was promoted to major general and served on the court-martial board that convicted Fitz John Porter. His dissenting voice in the final vote damaged his political clout. Prentiss was sent to Arkansas and won the Battle of Helena on July 4, 1863. In 1863, he resigned to tend to his family. Historian Ezra J. Warner speculated that Prentiss felt that he was being shelved after having proved his abilities at Shiloh and Helena.
https://en.wikipedia.org/wiki/Benjamin_Prentiss