He is generally acknowledged as the first major investment banker in the United States and creator of the first wire house firm.

[2] In the early months of the war, Cooke worked with Treasury Secretary Salmon P. Chase to secure loans from the leading bankers in the Northern cities.

Meanwhile, Cooke secured the support of most Northern newspapers, purchasing ads through advertising agencies, and often working directly with editors on lengthy articles about the virtues of buying government bonds.

His editorials, articles, handbills, circulars, and signs most often appealed to Americans' desire to turn a profit, while simultaneously aiding the war effort.

He sent agents into remote villages and hamlets, and even into isolated mining camps in the west, and persuaded rural newspapers to praise the loan.

[6] Although Cooke's bond campaigns were widely praised as a patriotic contribution to the Union cause, his huge personal financial gains did not go unnoticed.

Cooke moved to Duluth, Minnesota after purchasing land, particularly in Carlton and St. Louis counties, mostly through agricultural college scrip.

[7] However, in advancing the money for the work (especially on the railway), the firm overestimated its capital, and at the approach of the Panic of 1873 it was forced to suspend operations.

Jay Cooke was heavily involved in financial scandals with the Canadian government and caused the Prime Minister John A. Macdonald to lose his office in the 1873 election.

Cooke owned a summer home, constructed in 1864–65 and still standing, on the small island of Gibraltar in the Lake Erie harbor of Put-in-Bay, Ohio.

[citation needed] A devout Episcopalian, Cooke regularly gave 10 percent (a tithe) of his income for religious and charitable purposes.