Question: Who was the president that went into office after the assassination of the previous president and gave his State the Union Address when the American Civil War had ended?

<P0-S0> Hiester Clymer (1827 – June 12, 1884) was an American political leader from the state of Pennsylvania. <P0-S1>  Clymer was a member of the Hiester family political dynasty and the Democratic Party. <P0-S2>  He was the nephew of William Muhlenberg Hiester and the cousin of Isaac Ellmaker Hiester. <P0-S3>  Although Clymer was born in Pennsylvania, he was adamantly opposed to Abraham Lincoln's Administration and the Republican party's prosecution of the American Civil War. <P0-S4>  Elected Pennsylvania state senator in 1860, Clymer adamately opposed state legislation that supported the state Republican party's war effort. <P0-S5>  After the American Civil War ended, Clymer unsuccessfully ran for the Pennsylvania Governor's office in 1866 on a white supremacist platform against Union Major-General John W. Geary. <P0-S6>  After his election to the U.S. House of Representatives in 1872 as a Democrat, Clymer would be primarily known for his investigation of Sec. <P0-S7>  William W. Belknap's War Department in 1876. <P0-S8>  Belknap escaped conviction in a Senate trial, since he resigned his cabinet position before being impeached by the House of Representatives. <P0-S9>  Having retired from the House of Representatives in 1881, Clymer served as Vice President of the Union Trust Co. of Philadelphia and president of the Clymer Iron Co until his death in 1884. <SEP> <P1-S0>  It was presented to the United States Congress on Monday, December 4, 1865. <P1-S1>  He stated, "Our thoughts next revert to the death of the late President by an act of parricidal treason. <P1-S2> The 1865 State of the Union Address was written by the 17th President of the United States, Andrew Johnson. <P1-S3>  The grief of the nation is still fresh. <P1-S4>  It finds some solace in the consideration that he lived to enjoy the highest proof of its confidence by entering on the renewed term of the Chief Magistracy to which he had been elected; that he brought the civil war substantially to a close; that his loss was deplored in all parts of the Union, and that foreign nations have rendered justice to his memory." <P1-S5>  The American Civil War had ended, and now it was time for the Reconstruction era to begin. <SEP> <P2-S0>  Johnson became president as he was vice president at the time of the assassination of Abraham Lincoln. <P2-S1>  A Democrat who ran with Lincoln on the National Union ticket, Johnson came to office as the Civil War concluded. <P2-S2>  The new president favored quick restoration of the seceded states to the Union. <P2-S3>  His plans did not give protection to the former slaves, and he came into conflict with the Republican-dominated Congress, culminating in his impeachment by the House of Representatives. <P2-S4> Andrew Johnson (December 29, 1808 July 31, 1875) was the 17th President of the United States, serving from 1865 to 1869. <P2-S5>  He was acquitted in the Senate by one vote. <SEP> <P3-S0> The 1860 State of the Union Address was written by James Buchanan, the 15th President of the United States. <P3-S1>  It was read on Monday, December 3, 1860, to both houses of the 36th United States Congress, by a clerk. <P3-S2>  He stated, "Why is it, then, that discontent now so extensively prevails, and the Union of the States, which is the source of all these blessings, is threatened with destruction?" <P3-S3>  He spoke on the eve of the American Civil War.