Which would be considered a secondary source about the assassination of Abraham Lincoln?

s the president shall be commander in chief of the army and navy of the united states, and of the militia of the several states, when called into the actual service of the united states; he may require the opinion, in writing, of the principal officer in each of the executive departments. sooo yeahhh

explanation:

the answer is "focused on"

lol gave an answer 1 week that's the answer for those who need it in the future xd