The Civil War fiscal crisis began before April 12, 1861. The U.S. Treasury tottered in a state of utmost confusion months before the firing on Fort Sumter.
Traditionally the “dynamic center” of government, the Treasury now faced “being placed before the world in the aspect of a mendicant.” The department's secretary, John A. Dix, notified Congress on February 11, 1861 that “little more” than $500,000 remained in the central depository in Washington.
Demands for $2 million “unanswered” requisitions had accumulated in the department, with $6 million more due to public creditors in early March. Dix predicted a $21.6 million shortfall by the end of the fiscal year.
Staff in most executive departments could not draw their salaries that January. Members of Congress had gone unpaid since the start of the session the previous December. Worse yet, according to Dix, “The War and Navy departments have calls for large requisitions [that] have been delayed on account of the exhausted condition of the Treasury.”
These were all serious problems requiring attention from Congress, which soon enough took the actions necessary to correct them.
So in the end the US government did what it must to pay its bills and also win the Civil War.