The U.S. Capitol, newly constructed in 1860, was draped in black after Lincoln's shocking death. So was the place of the murder, Ford's Theater. Following a custom of the time, "mourning cards" were printed commemorating the life of the slain leader.
Grieving crowds thronged Washington's streets for the first of many funerals for the man who had been born on a corn-husk-covered bed in a nearly windowless, one-room Kentucky log cabin on "Sinking Spring Farm." (The link takes you to a nearly exact replica located at his birthplace.)
I knowed they'd kill him. I bin awaitin' fer it.
In 1865, Walt Whitman (whose poetry, among others Lincoln read) wrote O Captain! My Captain! to commemorate the President's death. Even in his lifetime, the poem became Whitman's most famous. It has been included in anthologies - one, the Riverside Literature Series No. 32, incorporated an earlier version which Whitman himself corrected - and referred to in movies (like Dead Poets Society starring Robin Williams and Ethan Hawke).
Despite the nation's overwhelming grief at the loss of its first assassinated President - who had delivered his second inaugural address a mere six weeks before his death - the military and civilian law enforcement officials directed their attention to capturing the escaped, still-at-large killer.