One hundred and fifty-one years after his heroism at Gettysburg and more than two decades after a senator took up his cause, First Lt. Alonzo H. Cushing will get his Medal of Honor.

Cushing was 22 when he died on July 3, 1863, during the pivotal Pennsylvania battle of the Civil War. On Sept. 15, President Obama will bestow the nation's highest military award on the Union Army officer, the White House announced Tuesday.

Members of the Wisconsin congressional delegation including Reps. James Sensenbrenner, a Republican, and Ron Kind, a Democrat, sought the award for the native of their state, pushing ahead with an effort begun in the 1980s by the late Sen. William Proxmire, D-Wis.

"It definitely falls into that category of it's never too late to do the right thing," Kind said in a phone interview. A Civil War buff and descendant of Union soldiers, Kind began working to get Cushing the medal when he was an intern for Proxmire in the 1980s.

"The memory of the Civil War still resonates loudly, even in Congress," he said. "I think there was a little bit of a delay in awarding this to a Union soldier who died at Gettysburg."

Obama will also award Medals of Honor on Sept. 15 to two Vietnam War veterans, Bennie Adkins and Donald Sloat. Adkins will attend the ceremony, the White House said. Sloat was killed in action Jan. 17, 1970, at age 20, and will receive the award posthumously.

Pickett's Charge

Cushing was commander of a Union artillery battery on the third day of the Gettysburg battle, during what's now known as Pickett's Charge, according to an account provided by the White House. After Confederate cannon fire ripped into his position, he took over firing the only artillery piece in his battery that was still operable.

During the fighting, he was severely wounded in the shoulder and stomach. Cushing refused to be moved to the rear and continued directing firing of the artillery piece until he was mortally wounded by a bullet.

"His actions made it possible for the Union Army to successfully repulse the Confederate assault," the White House account states.

Cushing was buried with honors at the U.S. Military Academy at West Point, N.Y., from which he graduated two years before his death.