On this day, exactly two and a half centuries ago, an Irish immigrant who had become one of Gen. George Washington’s trusted aides in the Revolutionary Army was the first person to use the name “United States of America.” Stephen Moylan played a key role in the American Revolution, but like his fellow Irish Catholic immigrant and George Washington’s favorite aide, John Fitzgerald, Moylan had been almost lost to history in the modern era. That is, he was overlooked until, at the close of the 20th century, a letter of his from Jan. 2, 1776, came to light that proved...