Hassam painted watercolor studies during his free time, and by 1879, he was making his first oil paintings. To make a living, the artist worked designing commercial engraving, becoming an official freelance illustrator and starting his own studio in 1882. Although Hassam was already a professional illustrator, he never stopped learning, attending classes at the Boston Art Club and the Lowell Institute. One year later, Hassam was showing his watercolor paintings in Boston in his first solo exhibit. During this time, he dropped “Frederick” of his name.

Like many other artists at the time striving for a successful career, Hassam decided to spend a couple of months abroad to study the works of the past masters in Europe. Along with Edmund Garrett - his friend who was also a member of the Boston Art Club - they traveled to Italy, France, the Netherlands, Spain, Switzerland, and the United Kingdom. Hassam was particularly taken by J. M. W. Turner’s watercolor landscapes, an inspiration for him to portray the European countryside during his trip as well. The Barbizon school and their way of painting directly from nature was an inspiration for Hassam, especially William Morris Hunt. In 1884, the artist married to Kathleen Maude Doane, a friend of the family, and during this period his interest in city-scapes increased.

Along with other American artists of the time, Hassam was going against the strict norms of the academy, like the traditional subject matters, preferring to portray the world he saw around him. In 1886, the painter and his wife moved near the Place Pigalle in Paris, the area where the art community frequently attended. He studied drawing under Jules Joseph Lefebvre and Gustave Boulanger. While in Paris, Hassam came in contact with Impressionist paintings in exhibits, and the avant guard style influenced his production.

Although throughout the 1890s, most modern artists were already leaning towards Fauvism and Post-Impressionism, Hassam’s watercolor and oil paintings became more Impressionistic. He and his family visited Europe, in locations like Rome, Florence, Paris, England, and Naples, where the artist took the opportunity to study the work of past masters in Museums, churches, and galleries. It was after his return to New York in 1897, that the painter formed The Ten, and is known as the most radical member of the group. After a period of struggling with depression and alcohol abuse during his mid-life, Hassam began having a different view upon life - reflecting on his artistic production, which involved some works in Neo-Classical themes. By 1909, the paintings of the American artist were very successful and sought after. One of Hassam’s most praised works is a series of flag paintings he began in 1916. He passed away in East Hampton, New York, on August 1935.