Le Clear sold his first paintings, copies of a painting of Saint Matthew, at the age of 12. He began to follow art professionally before he had had any instruction. He continued to teach himself by studying the painting by other artists. When he was fourteen, in 1832, he moved to London, Canada, with his father. He painted portraits there for a time. He painted portraits in Elmira, and in Rochester, before moving to New York City in 1839, when he was twenty-one. There he studied for several years under Henry Inman. From 1844 to 1860, he resided in Buffalo, where he was a founding member of the Buffalo Fine Arts Academy. He returned to New York City in the early 1860s, and was elected a National Academician in 1863.