Background: Thomas Cowperthwait Eakins (July 25, 1844 - June 25, 1916) was an American realist painter, photographer, sculptor, and fine arts educator. He is widely acknowledged to be one of the most important artists in American art history. For the length of his professional career, from the early 1870s until his health began to fail some 40 years later, Eakins worked exactingly from life, choosing as his subject the people of his hometown of Philadelphia. He painted several hundred portraits, usually of friends, family members, or prominent people in the arts, sciences, medicine, and clergy.
Context: Eakins' first works upon his return from Europe included a large group of rowing scenes, eleven oils and watercolors in all, of which the first and most famous is Max Schmitt in a Single Scull (1871; also known as The Champion Single Sculling). Both his subject and his technique drew attention. His selection of a contemporary sport was "a shock to the artistic conventionalities of the city". Eakins placed himself in the painting, in a scull behind Schmitt, his name inscribed on the boat.  Typically, the work entailed critical observation of the painting's subject, as well as preparatory drawings of the figure and perspective plans of the scull in the water. Its preparation and composition indicates the importance of Eakins' academic training in Paris. It was a completely original conception, true to Eakins' firsthand experience, and an almost startlingly successful image for the artist, who had struggled with his first outdoor composition less than a year before. His first known sale was the watercolor The Sculler (1874). Most critics judged the rowing pictures successful and auspicious, but after the initial flourish, Eakins never revisited the subject of rowing and went on to other sports themes.  At the same time that he made these initial ventures into outdoor themes, Eakins produced a series of domestic Victorian interiors, often with his father, his sisters or friends as the subjects. Home Scene (1871), Elizabeth at the Piano (1875), The Chess Players (1876), and Elizabeth Crowell and her Dog (1874), each dark in tonality, focus on the unsentimental characterization of individuals adopting natural attitudes in their homes.  It was in this vein that in 1872 he painted his first large scale portrait, Kathrin, in which the subject, Kathrin Crowell, is seen in dim light, playing with a kitten. In 1874 Eakins and Crowell became engaged; they were still engaged five years later, when Crowell died of meningitis in 1879.
Question: When did his career begin?

Answer:
(1871;