Now the trumpet summons us again — not as a call to bear arms, though arms we need — not as a call to battle, though embattled we are — but a call to bear the burden of a long twilight struggle, year in and year out, rejoicing in hope, patient in tribulation — a struggle against the common enemies of man: tyranny, poverty, disease and war itself.

John F. Kennedy (1917-1963) American politician, author, journalist, US President (1961–63)

Inaugural address (20 Jan 1961)
    (Source)

Portions of this are one of the seven quotations by JFK at his grave site in Arlington National Ceremony.