Joseph Holt General Joseph Holt ( January 6 , 1807 – August 1 , 1894 ) was a leading member of the Buchanan administration and was Judge Advocate General of the United States Army , most notably during the Lincoln assassination trials . Early life . Born in Breckinridge County , Kentucky , on January 6 , 1807 , he was educated at Saint Joseph ' s College in Bardstown , Kentucky and Centre College in Danville , Kentucky . He settled in Elizabethtown , Kentucky and set up a law office in town . He married Mary Harrison and moved to Louisville , Kentucky in 1832 . There he became assistant editor of the Louisville Advertiser and the Commonwealth ' s Attorney from 1833 to 1835 . Holt moved to Port Gibson , Mississippi , and practiced law there , as well as in Natchez , Mississippi and Vicksburg , Mississippi . Holt and his wife contracted tuberculosis . Mary died of it , and Joseph returned to Kentucky to recuperate . James Buchanan ' s administration . Holt remarried , to Margaret Wickliffe . In 1857 , Holt was appointed Commissioner of Patents by President Buchanan , and moved to Washington . He served in this position until 1859 when Buchanan appointed him Postmaster General . The Buchanan administration was shaken in December 1860 and January 1861 , when the Confederacy was formed and many cabinet members resigned , but Holt was anti - slavery and a strong supporter of the Union . He was appointed Secretary of War upon the resignation of John B . Floyd of Virginia . Holt served as Secretary of War until the end of Buchanan ' s presidency . Judge Advocate General . Holt joined the Army as a colonel in 1862 and was appointed by President Abraham Lincoln to be the Judge Advocate General of the Union Army ; two years later , he was promoted to brigadier general . He was the first Judge Advocate General to hold general ' s rank . In this position he personally prosecuted the court - martial against Maj . Gen . Fitz John Porter for crimes of disobedience of a lawful order and misbehavior in front of the enemy . Lincoln also offered Holt the position of Secretary of the Interior that same year and Attorney General later in 1864 , but Holt declined both offices . He was one of the many politicians considered for the Republican nomination in 1864 . The VP nomination went to Andrew Johnson , and Lincoln was re - elected . Abraham Lincoln assassination . On April 14 , 1865 , President Lincoln was assassinated by Confederate sympathizer John Wilkes Booth . Booth ' s accomplice Lewis Powell attacked Secretary of State Seward , and Vice President Johnson was also targeted . Holt prepared an order for the signature of now - President Johnson for the arrest of Confederate President Jefferson Davis and five other suspects . Booth was caught on April 26 , 1865 , but was killed by Boston Corbett , a soldier who violated orders . As Judge Advocate General of the Army , Holt was the chief prosecutor in the trial of the accused conspirators before a military commission chaired by General David Hunter . Two assistant judge advocates , John Bingham and General Henry Burnett assisted Holt . The defendants were George Atzerodt , David Herold , Lewis Powell ( a / k / a Paine ) , Samuel Arnold , Michael O ' Laughlen , Edman Spangler , Samuel Mudd , and Mary Surratt . The trial began on May 10 , 1865 , and lasted two months . Holt and Bingham attempted to obscure the fact that there were two plots . The first plot was to kidnap Lincoln and exchange him for Confederate prisoners held by the Union . The second was to assassinate Lincoln , Johnson and Seward and throw the government into chaos . It was important for the prosecution not to reveal the existence of a diary taken from the body of Booth . The diary made it clear that the assassination plan dated from the 14th of April . Surprisingly , the defense did not call for Booth ' s diary to be produced in court . Holt was accused of withholding evidence , but it was never proven . On June 29 , 1865 , the eight were found guilty of conspiracy to kill the President . Arnold , O ' Laughlen , and Mudd were sentenced to life in prison , Spangler to six years in prison , and Atzerodt , Herold , Powell , and Mrs . Surratt to be hanged . Mrs . Surratt became the first woman executed by the United States federal government since its formation . They were executed July 7 , 1865 . O ' Laughlen died in prison in 1867 . Arnold , Spangler , and Mudd were pardoned by President Johnson in early 1869 . Accusations still remain that Mrs . Surratt ' s sentence of hanging was reduced but that Holt purposely delayed its taking effect until it was too late . Holt ' s public image was besmirched by the trial and his prosecution of it , and many historians believe that the controversy surrounding it ended Holt ' s political career . In 1866 , Holt issued a pamphlet titled " Vindication of Judge Advocate General Holt From the Foul Slanders of Traitors , Confessed Perjurers and Suborners , Acting in the Interest of Jefferson Davis " in which he attempted to defend himself against the various allegations and clear up some of the confusion stemming from the trial . Later life . Holt served as Judge Advocate General until he retired on December 1 , 1875 . He had a quiet retirement and died in Washington on August 1 , 1894 . He is buried in the Holt Family Cemetery in Stephensport , Kentucky . Holt County , Nebraska is named after him .