With the united States pre-occupied with suppressing Confederate independence, Juan Prim y Prats, Count of Reus commanding the Tripartite Alliance docks at Veracruz, Mexico, in an effort to collect on defaulted loans made by private banks in the Empire of France, the Kingdom of Spain and the United Kingdom.

       [added 3/26/2022]

Subsequent Events:

References:

French intervention in Mexico – Wikipedia, the free encyclopedia
en.wikipedia.org/wiki/French_intervention_in_Mexico

Juan Prim – Wikipedia
en.wikipedia.org/wiki/Juan_Prim

Current U.s. National Debt:

$36,161,621,015,445

Source