In the late 18th century before the Revolutionary War, a good number of English citizens were pish-poshing the very idea of a United States of America.

So the thought of former colonists creating any kind of unique art worth looking at -- much less comparing to centuries of British tradition -- was not keeping many of King George's gallery walkers up at night.

But nobody told that to Benjamin West and John Singleton Copley. Though the American-born artists (Pennsylvania and Massachusetts respectively) had relocated back to the mother country by the time the first shots were fired at Lexington and Concord, their unique American perspective and practice of a new genre of painting ensured their massive success in London.

Unfortunately, the formerly close friends also became bitter rivals. Their work, evolving personal relationship, and the growing global culture in which they lived in is the focus of the new Museum of Fine Arts original exhibit, "American Adversaries: West and Copley in a Transatlantic World."

The exhibit -- curated by Copley expert Emily Neff and West expert Kaylin Weber -- will feature oil paintings, works on paper, sculptures, and items from both men's lives and careers.

"West and Copley created a new kind of painting called 'contemporary history.' And while artists before them had painted images of current events like battles, none had done with all the bells and whistles that they brought to the table," Neff says.

"The paintings were large scale, contained references to Greek and Roman and Old Masters art, and were dramatic and theatrical. It was an utterly new approach at the time."

Also on display are works by their contemporaries and other artifacts (like some collected on Captain James Cook's voyages to the Pacific Ocean) to help illustrate the emerging "global" culture that West and Copley lived through. It was a time when intercontinental travel and culture-sharing became more frequent.