[Sherman Logan]

Before 1861, the United States were loosely tied entities and always described as a plural noun, as in, "The United States are in trade with France."

This is commonly believed but actually not true.

The United States was used as both a singular and plural noun almost from the beginning, with a gradual shift from singular to plural in frequency.

The biggest jump in the shift came during and after the War of 1812, with another during the Civil War. The process was pretty much complete by 1900.

[FrdmLvr]

I was taught the country was originally referred to as the united states of America, small u, small s.

[daniel1212]

Thanks. Glad to have historian types here.