Slideshow: Unsung heroes of the Civil War

Sgt. William Harvey Carney received the Medal of Honor for his heroic actions at the Battle of Fort Wagner. He was the 21st African-American to be awarded the Medal, but the first whose actions led to receiving one.

Robert Smalls was an enslaved African American who became a sea captain and politician. He freed himself and his family by commandeering a Confederate transport ship to freedom in Charleston. He also founded the Republican Party of South Carolina and convinced Pres. Lincoln to accept black soldiers into the Union army.

Robert Gould Shaw was born to a prominent abolitionist family. He was a Union colonel who commanded the all-black 54th Regiment. Shaw was killed in an attempt to capture Fort Wagner in 1863.

Andre Cailloux was one of the first black officers in the Union Army to be killed in combat. His death was widely reported in the press and was the catalyst for the recruitment of African Americans in the Union.

John F. Reynolds was one of the Union's most respected generals. Although he initially had little combat experience in the war, he led the Army of the Potomac to the Battle of Gettysburg. He was killed at the start of the battle.

Robert Blake was a Union Navy sailor and was the second African-American to receive the military's highest decoration, the Medal of Honor.

Charlotte Grimke was the first black teacher to join the Civil War's Sea Islands mission. She worked with former slaves as a teacher and volunteered as a nurse for the members of the all black 54th regiment in the Union Army.

Mathew Brady is credited as being the father of photojournalism. His documentation of the Civil War, including graphic photos of the Battle of Bull Run and Antietam, have earned him a place in history.

In 1864, Decatur Dorsey served in the Battle of the Crater In VA and detonated explosives beneath Confederate lines. The blast allowed white Union soldiers to attack through the resulting crater. He received the Medal of Honor.

Abner Doubleday fired the first shot while defending Fort Sumter in the opening battle of the war. He was a Union general and played a pivotal role in winning the Battle of Gettysburg. He is also mistakenly credited with having invented baseball.

At the Battle of Mobile Bay in 1864, Mifflin successfully performed his ammo supply duties under constant enemy fire. A ship was named in his honor (USS Mifflin) and participated at Iwo Jima and Okinawa during WWII.

Powhatan Beaty served in the Union's 5th Colored Infantry Unit. He took command of his company at the Battle of Chaffin's Farm after all the officers had been killed or wounded.

William Plummer Benton was a lawyer and soldier who rose to the rank of major general for the Union Army. He led the 8th Indiana Volunteer Infantry Regiment in some very early battles, such as the Battle of Rich Mountain.