Childe Hassam saw himself as an American artist seeking to invest Impressionism with an American spirit. Throughout his life, he depicted places and structures of local significance and often painted people he knew. An Outdoor Portrait of Miss Weir not only documents Hassam's mature Impressionist style, it also testifies to his longstanding friendship with fellow American Impressionist J. Alden Weir, as it depicts one of Weir's three daughters.

Born in Dorchester, Massachusetts, to an old New England family, Hassam was apprenticed to a local wood engraver in 1876 and soon became a freelance illustrator. In the evenings, he attended the Boston Art Club's life class, and then briefly studied anatomy with William Rimmer at the Lowell Institute. Hassam made his first trip to Europe in 1883, visiting galleries and museums. He returned for a more extended stay in 1886. In Paris, he enrolled at the Académie Julian and exhibited at the Paris Salon. Immersed in Impressionist strategies and techniques, he produced numerous plein-air paintings that made him the central figure in an emerging group of progressive American painters. He returned to Boston in 1889 and eventually settled in New York City.

Hassam was a prominent artist in New York and in 1898 became a founding member of the Ten American Painters (also known as "The Ten"). From New York, he made repeated visits to Appledore Island, Maine, one of the Isles of Shoals, where he spent summers and created more than 4,000 works in both oil and watercolor. In the 20th century, he also painted in California and Oregon, where the landscape and light of the West inspired him.