The artist Leon Polk Smith was born in 1906 in Oklahoma, to half-Cherokee parents. As a young man he worked as a ranch hand before heading west to Arizona. Everything changed at age 30, when Smith moved to New York City to train as a teacher. A trip to the Gallatin Collection, where he saw Mondrian’s balanced geometries and Brâncuși’s serene sculptures, convinced him to become an artist. Before long, Smith created his own variation of De Stijl, producing abstraction that was energized by strong curving forms. “People said Mondrian had hit a dead end, or a stone wall,” Smith once observed, “and I said, I don’t think so.” In this exhibition, Smith’s midcentury paintings and works on paper show his pioneering approach, known as “Hard-Edge Painting.” —Elena Clavarino