Final answer:
Jefferson Davis thought the situation was very serious as he faced the possibility of being charged with treason and executed, reflecting the public's and authorities' harsh attitudes post-Lincoln's assassination.
Step-by-step explanation:
From the provided text, we glean that Jefferson Davis viewed his situation as extremely serious. After the assassination of Abraham Lincoln, Davis was captured and taken to Fort Monroe, Virginia amidst the investigation. The severity of his situation is underscored by the belief held by many that Davis, and by extension the Confederate government, had ties to Lincoln's assassination. While this was later disproven, the atmosphere was wrought with high emotions, leading to strong claims in magazines and papers, such as Harper's Weekly, that urged for Davis to be charged with treason and potentially executed upon conviction. These descriptions of the legal and public sentiment threats towards Davis signal the gravity he faced.