At antietam: general lee was successful and pushed north into pennsylvania. general mcclellan surrendered his troops. the nation suffered more casualties than on any other day in its history. the union's river fleet proved crucial to the outcome. lincoln announced the thirteenth amendment.

At Antietam the nation suffered more casualties than on any other day in its history.

Explanation:

The Battle of Antietam, also known as the Battle of Sharpsburg, was an armed clash that took place on September 17, 1862 near the city of Sharpsburg, Maryland in the United States during the Civil War.  

Total losses amounted to over 23 thousand soldiers in one day of battle. It was the bloodiest day in all of US history.  

This battle is considered a breakthrough moment in the war, because from then on, despite a number of further victories, the advantage of the Southerners began to decrease markedly, which eventually led to the Union's victory two and a half years later.

the assassination of president lincoln was just one part of a larger plot to decapitate the federal government of the u.s. after the civil war. the first reaction to lincoln’s death was disbelief. then it quickly changed to grief. abraham lincoln’s death created an outpouring of grief from citizens in both the north and the south.

explanation:

lincoln was the first u.s. president to be assassinated. president abraham lincoln, america’s civil war leader, was assassinated just five days after confederate general robert e. lee surrendered his army at appomattox court house, ending the four-year war between the states. on the evening of april 14, 1865, lincoln was attending a performance of our american cousin at ford’s theatre in washington, d.c. john wilkes booth – a 26-year old actor, confederate sympathizer, and white supremacist – slipped into the presidential box and shot lincoln in the head. john wilkes booth and his conspirators had initially planned to kidnap lincoln to save the confederate states. but as the confederacy faltered, booth’s thoughts turned to murder. booth may have decided to act on his hatred after lincoln endorsed giving the right to vote to african-american men who had served in the union army.

the answer you are looking for is letter c. he supported the idea of a un-run war in serbia to bring peace to the area.

supporting this idea was an important step that bill clinton took in order to attempt to secure bosnia and keep the peace there. he led peace reconciliations -known as the dayton agreement- leaving bosnia as a single state made up of two parts with one central government.