At his suggestion the five arbitrators announced on June 19, 1872, that they would not consider claims for indirect damages, because such claims did "not constitute, upon the principles of international law applicable to such cases, good foundation for an award of compensation, or computations of damages between nations." These claims dismissed, the arbitrators entered into an examination of the direct American claims and on September 14, 1872, decided upon an award of fifteen and a half million dollars to the United States.

The Treaty of Washington and the Geneva Tribunal constituted the longest step thus far taken by any two nations toward the settlement of their disputes by judicial process..