Nicolai Cikovsky Jr., an art historian who became a curator at the National Gallery of Art, where he took a leading role in organizing several major exhibitions, including a 1995 retrospective of the works of painter Winslow Homer, died May 1 at his home in Washington. He was 83.

Dr. Cikovsky, whose father was a painter, developed an interest in 19th-century American art as a student and became a leading authority on such painters as Homer, William Merritt Chase, George Inness and Samuel F.B. Morse.