Paine published The American Crisis No. 1, by far the most famous of the pamphlet series, in December of 1776, a time in which American fortunes in the Revolutionary War were at a low ebb. This was the time when the Americans had been driven from the vicinity of New York City after the campaign on Long Island, a campaign from which George Washington and his forces narrowly escaped total destruction. Additionally, the enlistment terms of many in the Continental Army were up on January 1, which meant that Washington's army, already outmanned, was threatened with disintegration with morale very low. So Paine's American Crisis was intended to be a sort of rallying cry for the Americans, both on the home front and among the Continental Army especially, to whom Washington had it read aloud.
Paine is basically urging Americans to continue fighting the good fight against the British. He opens by acknowledging that "these are the times that try mens' souls," and urges Americans to regard this as a challenge to be overcome rather than a source of disillusionment or despair:
The summer soldier and the sunshine patriot will, in this crisis, shrink from the service of their country; but he that stands by it now, deserves the love and thanks of man and woman.
He goes on to argue, basically, that the Americans cannot lose, because they are in the right, and God favors the right. But the fight will be long and difficult, because "tyranny, like Hell, is not easily overcome." To demonstrate that Providence is in favor of the Americans, he offers the Continental Army's narrow escape from Long Island as an example, praising the army's "manly and martial spirit" in the retreat, conducted by Washington, who he compares favorably to great European military leaders.
The last part of the essay is somewhat less uplifting. In it, he urges firmness in dealing with the many Loyalists that populate Pennsylvania and the South. He points out that the war could be financed by confiscating their property and states his wish that these enemies of the Revolution should be expelled from the continent. Finally, after restating his belief that the Americans will, in the end, win independence, he offers a nightmarish alternative, predicting that, if they win, the British will not deal mercifully with American rebels. Even ordinary Americans will find their homes and families ravaged by the British and their Hessian allies.
In short, Paine seeks to steel the American people for the sacrifices he knows are coming soon. The American Crisis is a famous piece of wartime propaganda by a master of the art.