These are the top 5 military-related presidential pardons

The Constitution (Article II, Section 2, Clause 1) gives American presidents the power to grant full pardons. Throughout history, presidents have used this power, some more than others. Presidents Harrison and Garfield issued zero pardons, mostly because both of them died shortly after taking office. (Harrison died of pneumonia and Garfield was assassinated.) President Franklin Roosevelt issued 3,687 pardons, but a factor in that total is the fact he held office for 12 years. President Andrew Johnson either pardoned over 7,000 or just 654 people, depending on how you score it. The average number of pardons per president to date is just over 665.

Pardons have taken many forms. Some have been high-visibility because of their impact on politics and pop culture like when President Ford pardoned former President Nixon or when President Clinton pardoned publishing heir Patty Hearst following her stint as a domestic terrorist. Some have been personal like when President Clinton pardoned his brother Roger following a conviction on cocaine possession charges. But presidents also being commanders-in-chief, naturally, some pardons in American history have had something to do with the military.

In the mid-1800s the Buchanan administration grew concerned about the activities of the Latter Day Saints, led by Brigham Young. The president was afraid that Young was on the verge of creating a theocracy out west and so he sent the U.S. Army to intervene. The resulting "Utah War" was mostly without bloodshed, with the notable exception of the time some Mormons murdered 12o settlers from Arkansas. Young was accused of giving the order or, at least, not doing enough to prevent it. He was later able to prove that he'd actually sent a dispatch ordering his people to let the settlers pass in peace, but it got there two days after the massacre. As a result, Young was ultimately pardoned by President Buchanan.

During the election seasons in the years immediately following the Civil War, it became politically expedient to get the conflict behind the country. In fact, the U.S. Senate was so disappointed in President Johnson's Reconstruction progress that they impeached him. So on Christmas Day in 1868, Johnson offered amnesty to all Confederates. At about the same time he also pardoned Dr. Samuel Mudd, the Maryland doctor who patched up Lincoln's assassin John Wilkes Booth. President Grant, who'd led the North to victory as a Union general, finished the process, later signing the Amnesty Act of 1872, which pardoned all but 500 of the top Confederate leaders.

Iva Toguri D'Aquino was an LA native Japanese-American who had the misfortune of being in Tokyo when war broke out between the U.S. and Japan. She became the voice of Japanese propaganda aimed at American servicemembers across the Pacific Theater. She was frighteningly accurate with military details from time to time, which did cause GIs some concern, but she was also a source of entertainment for them because her broadcasts were equally campy as provocative.

When the war ended "Tokyo Rose," as D'Aquino was popularly known, was charged with treason, convicted and imprisoned until 1956. In time the facts emerged that she had been pressed into service for the Japanese war machine under duress. She was pardoned by President Ford in 1976.

William Calley was a community college dropout who found himself in charge of a platoon fighting the Vietnam War. His weak leadership and lack of military skill led to the systematic murder of 500 Vietnamese civilians. Life magazine broke the story over a year and a half later with a graphic photo essay that shocked the nation and did much to shift public sentiment against the war once and for all.

Calley's court-martial was a high-visibility event, and he was eventually found guilty of 22 counts (of the 109 he was charged with) of premeditated murder. He was sentenced to life imprisonment at Leavenworth. President Nixon, reacting to another public sentiment that Calley had been made a scapegoat and that the punishments should have gone higher up the chain of command, ordered his sentence modified to house arrest. Eventually, his time was reduced from life to 20 years. He served three and a half years of that when Nixon pardoned him.

In 2009, while speaking a Kiwanis Club in Ohio, Calley issued the following apology for his role at My Lai:

Although Gerald Ford had been the first to deal with letting draft dodgers off the hook, his version had been conditional and only affected one-third of the population. President Carter, elected on a progressive agenda, took it the rest of the way by issuing an unconditional pardon for all of those who'd evaded the draft, about 150,000 young American men -- including a number of aspiring politicians who would go on to hold the highest offices in the land.