Henry worked tirelessly to support the field of American science. He encouraged young scientists and provided living quarters in the Castle for them. Henry participated, and often led, American science societies including the National Academy of Science and the US Lighthouse Board. Additionally, Henry traveled to Europe engaging in scientific discussions and promoting American science abroad. He kept the Smithsonian going during the difficult Civil War years, and served as one of President Abraham Lincoln’s science advisors. Henry handled the budget issues the war caused and even sent a memo asking people to save paper so that it might be re-sold. The Institution also helped in the war by cooperating with the Sanitary Commission and Surgeon-General of the US Army in improving the health and comfort of soldiers, while at the same time collecting data of interest to ethnologists and other researchers.