In 1927 he joined the faculty at Brown University, where he taught for fourteen years and did research on the behavior of primates.

During Carmichael's tenure, the National Portrait Gallery was created, the Patent Office Building was acquired for the American Art and Portrait Galleries, and the Museum of History and Technology (now the National Museum of American History) was opened.

After the death of a visitor at the National Zoological Park, Carmichael sought additional funding for major improvements to meet safety regulations.

[3] After leaving the Smithsonian, Carmichael became vice-president for research and exploration of the National Geographic Society.

In 1972 he was awarded the Public Welfare Medal from the National Academy of Sciences, of which he was also a member.