On November 6 the Medal of Honor was posthumously awarded to a Union soldier who died at the Battle of Gettysburg and presented to his closest living relative, Helen Loring Ensign/US Army

More than 151 years after 1st Lt. Alonzo H. Cushing was killed at Gettysburg, he has been honored for his gallantry in battle with the Medal of Honor. President Barack Obama posthumously awarded the medal on November 6 in a ceremony a military historian said "rectified an ommission."

Lt. Cushing is the only soldier to posthumously receive the Medal of Honor for actions performed at Gettysburg, and now holds the record for greatest length of time between the presentation of the medal and the act for which it was bestowed, over 151 years.

In addition to the medal, Cushing is honored in Gettysburg National Military Park with two separate memorials. A granite marker indicates where his battery was positioned on July 3, 1863, and a small stone memorial pays tribute to Cushing himself and stands not far from where he fell during the climactic moment of the battle.

Though only 22 years old, 1st Lt. Cushing commanded the six rifled guns and 126 men of Battery A, 4th U.S. Artillery during the battle of Gettysburg, July 1-3, 1863. Positioned along the crest of Cemetery Ridge on July 3rd, Cushing's battery was subjected to a murderous two hour artillery barrage which proceeded Picket's Charge. Despite being wounded twice, once in the shoulder and a more serious wound in the abdomen, Cushing refused to abandon his position or his men, and actually advanced his remaining guns as Confederate infantry assaulted his position.

Severely wounded and urged by his first sergeant to retire, he swore that he would "fight it out, or die in the attempt."

As he was in the act of shouting orders to his men, an enemy bullet struck Cushing in the mouth, killing him instantly. His body was removed from the field and interred in the cemetery at the West Point Military Academy, where Cushing had graduated in 1861.

The award was presented to his closest living relative, cousin Helen Loring Ensign, 85, of California. Although his heroism was undisputed and widely recognized, he was not nominated for the award until recently. This was largely due to the efforts of amateur historian Margaret Zerwekh, who researched the family after moving to the Cushing homestead in Delafield, Wisconsin.

After President Obama announced in late August that Cushing would receive the honor, it took the Army Past Conflict Repatriations Branch "weeks" to find the closest living relative.

The ceremony "reflects our obligation to our men and women in armed services," President Obama said. "No matter how long it takes, it is never too late to do the right thing."