Gradually, however, he was brought around, mainly through the influence of his friends John Twachtman and Theodore Robinson. Together they explored the techniques of Japanese prints, carefully assessing the aesthetic function of flat patterning, cropping asymmetry, oblique angles, muted tonalities, and high horizons.
Weir had purchased a large farm property in Branchville, Connecticut, and like Twachtman employed its topographical resources for his landscape studies.
In 1897, with Twachtman and Hassam, he formed the group of Ten American Painters and exhibited with them for two decades. He was also a close friend and admirer of that solitary genius Albert Pinkham Ryder, caring for him in his illness and attending to the details of his hospitalization and funeral.
As Weir slowly moved toward impressionism, he painted attractive if somewhat idealized pictures of the factories at nearby Willimantic and, perhaps most dramatically, the Red Bridge that spanned the Connecticut River. As art historian William Gerdts writes, "the high horizon, the assertive geometry of the composition and especially its dominant diagonals suggest its derivation from Japanese art!" In the last decade of his life, although he had been an avid proponent of modernism, his own work came full circle, returning to a stodgy academicism.