The 1907 crisis that prompted J.P. Morgan to organize private support for banks was the Panic of 1907.
The panic began after a failed attempt to corner the stock of United Copper Company. Depositors then withdrew funds from banks and trust companies connected to the speculators, especially the Knickerbocker Trust Company in New York. The institution suspended operations in October 1907.
J. Pierpont Morgan gathered bankers in his library and helped coordinate emergency lending and asset support. The intervention reduced the immediate danger, but it also exposed how heavily the United States depended on one powerful private financier during a banking emergency.
The panic helped build political support for monetary reform. In 1913, the Federal Reserve System was created to provide a more systematic lender of last resort and to improve the stability of the American banking system.