How did Booth feel about the nation’s reaction to the assassination?

That sentiment carried over after Lincoln's assassination. In a letter to the New York Afro-African newspaper, one writer said that Booth had "murdered their best friend," and the sentiment of Lincoln as a friend was a common one among Lincoln's sympathizers.

the following key ideas correctly express the key sentence.

restate key idea: most people can learn to swim in ten short lessons.

restate key idea: the majority of water-accident victims require mouth-to-mouth breathing.

restate key idea: an empty, tightly closed gallon jug will support a tired swimmer.  

restate key idea: first aid is to prevent accidents as well as assist in rescue.

explanation: the key idea needs to have the same topic as the key sentence (drowning and safety).