His name is sometimes listed as "Axel Horr" as an erroneous reading of his signature on paintings; this error[2] is reflected in the Archives of American Art, leading to confusion over his surname.

[4] As a member of the Federal Art Project, and he painted murals at the New York City Farm Colony and Seaview Hospital, Bellevue Hospital Center,[5] Welfare Island Nurses Home, Whitehall, New York Post Office,[6] and "Preparation for Lifework" in the Yellow Springs, Ohio Post Office.

In the 1960s, his concern for environmental issues led him to work on environmental and educational study programs for various colleges, agencies, foundations, and private firms, including the New York Botanical Garden, City University of New York, the National Science Foundation, Xerox, and the United Nations.

[9][better source needed] From 1966 to 1968, he worked for the Community Science Center in Ahmedabad, India, as a consultant, planner, co-administrator, and designer of environmental and educational systems.

[10][better source needed] From 1982 until his death, he continued to paint and write in his historic home, Shaker Hollow,[11] in Westchester County, New York.