After the American Revolutionary War broke out in the same year, Salomon supported the Patriots by providing financial services while working alongside Robert Morris, the Superintendent of Finance of the United States.

He helped convert French loans into hard currency by selling bills of exchange on Morris' behalf, and also brokered large donations to the Patriot cause.

Despite donating his entire fortune to the Continental Army and several Founding Fathers of the United States, Salomon died penniless in Philadelphia in 1785 due to the failure of government officials and private lenders to repay the debt they owed to him.

Salomon used his new position to help prisoners of war from the Continental Army escape, encouraged Hessian troops to desert, and collaborated with Hercules Mulligan and Cato to carry out other acts of espionage.

[7] From the period from 1781 to 1784, records show Salomon's fundraising and personal lending helped provide over $650,000 ($14.3 million in 2023) in financing to General George Washington in his war effort.

[5] Salomon brokered the sale of a majority of the war aid from France and the Dutch Republic, selling bills of exchange to American merchants.

Salomon was involved in Jewish community affairs, being a member of Congregation Mikveh Israel in Philadelphia, and in 1782 made the largest individual donation toward the construction of its main building.

In 1783, Salomon was among the prominent Jews involved in the successful effort to have the Pennsylvania Council of Censors remove the religious test oath required for office-holding under the State Constitution.

His obituary in the Independent Gazetteer read, "Thursday, last, expired, after a lingering illness, Mr. Haym Salomon, an eminent broker of this city, was a native of Poland, and of the Hebrew nation.

The east wall has a marble tablet that was installed by his great-grandson, William Salomon, and a granite memorial is set inside the cemetery gate.

A blue ribbon panel and committee, including Robert S. Whitman, Sidney Bruskin and Marvin Abrams, all lodge past presidents; and Philadelphia residents, arranged for the renovation of the walls and walkways of the cemetery.

They then arranged for and oversaw the installation of a large, engraved memorial marker of Barre Granite just inside the cemetery gates, inscribed "An American Patriot".

[13] There is a legend that during the design process of the Great Seal, Washington asked what compensation Salomon wanted in return for his financial contributions to the American Revolutionary War.

[15] When Morris was appointed Superintendent of Finance, he turned to Salomon for help in raising the money needed to carry on the war and later to save the emerging nation from financial collapse.