Adams was born on a farm in rural Indiana near Muncie. His father, a horse farmer and amateur artist, encouraged the younger Adams’ interest in art. At age twenty-one, Adams moved to Indianapolis to attend the John Herron Art Institute. There, he began to paint portraits.
He took two trips to Europe, the first in 1910 when he traveled to Italy with William Merritt Chase. Two years later, he accompanied Robert Henri to Spain where he met fellow artist Margaret Boroughs, whom he married six years later. In 1914, Adams painted a series of portraits for the city hospital in Indianapolis. He was to paint children whose families had been in the United States for generations and also children of immigrants to represent the various nationalities of which the city was composed. It was considered to be one of the most ambitious public art projects in Indiana’s history. Originally, twenty-four portraits were to be done; while some are now missing, they were all initially installed in the pediatric ward of the hospital.
After painting a portrait of author Booth Tarkington, which brought him fame, Adams relocated to New York City and studied at the Grand Central Art School. He favored the alla prima style of painting modeled by Chase and Henri. He would paint an entire portrait in one sitting, sometimes in only three to four hours. Adams became well known as a “lightning” artist and recorded many prominent figures, including Presidents Warren Harding, Calvin Coolidge and Herbert Hoover; tire tycoon B. F. Goodrich; golfer Bobby Jones; and actor Otis Skinner. He exhibited at the National Academy of Design, the Art Institute of Chicago, the American Watercolor Society, the Salmagundi Club, the Pennsylvania Academy of Fine Arts, the Carnegie Institute, the Hoosier Salon, and many other institutions. One of his best known works is a portrait of the Russian cellist Gregor Piatigorsky, which won a prize from the Carnegie Institute in Pittsburgh.
A member of the National Academy of Design, Adams also was a teacher. In 1932, he and his wife opened and taught at the Old Mill Art Colony in New York's Adirondack Mountains; from 1935 to 1936, he taught in Taxco, Mexico. In 1948, Adams retired to his wife’s hometown of Austin, Texas, where he remained active in the city’s artistic circles until his death.
Adams' work is represented in the collections of the Indianapolis Museum of Art, Art Institute of Chicago, the Yale University Art Gallery, the San Antonio Museum Association, the Texas State Library, and other institutions.