Unlike the French Impressionists, there was really no formal group that called themselves “American Impressionists”; this is a label writers have applied to American painters who adopted elements of Impressionist style and technique to their work.
There was however, “The Ten American Painters”, a group of painters from New York and Boston who withdrew from the Society of American Artists in protest of that group’s commercialism and restrictive styles, and devoted themselves to new styles of painting, largely influenced by French Impressionism. The group includes John Henry Twatchman, Edmund Charles Tarbell, William Merritt Chase and J. Alden Weir, among others.
One of the founding members of that group, and along with Tarbell and Chase, one of the most important of the painters referred to as “American Impressionists”, was Massachusetts painter Childe Hassam (pronounced “child HASS-em”).
Hassam started as an illustrator and worked primarily in watercolor. He went to Paris in search of a formal art education (as was common for American artists at the time) and studied oil painting at the Académie Julian. He later discounted that teaching but returned from Paris dramatically impressed (if you’ll excuse the expression) with the daring new style of those radical upstarts from the Salon de Refusés, the Impressionists.
His own work showed that influence in many ways, there are numerous paintings of flower gardens bursting with dabs of pure color, street scenes with finely dressed gentry awash in dappled sun and landscapes blanketed in brightly lit snow. But he also diverged in may ways from the Impressionist path.
His work would often dwell on themes of rain-drenched streets, late day sun and misty twilight, more in keeping with the muted whispers of Whistler’s nocturnes than the mid-day kaleidoscopic dazzle of Monet. He would break his color into rough chunks and patches, very different from the individual dabs of “pure color” favored by Impressionist theory, and explore the rich darks of room interiors, like his fellow member of “The Ten”, Edmund Tarbell.
Hassam was also a superb etcher, again more akin to Whistler than the Impressionists. There are excellent examples of his work in major museums in the US, particularly, as you might expect, on the East Coast.
Like the French Impressionists, the American Impressionists are popular subjects for publishers and there are numerous books on Hassam and his explorations of brilliant color and subtle light.