Harvard was able to secure substantial new funding for its botanical programs in the years after the war, but Gray encountered significant trouble finding a suitable replacement for his professorial duties. The American university system had failed to train replacements for its professors. Only Harvard and Yale had botany programs, and in the war and pre-war years there had been few botany students. However, after the war there was an upswing in the numbers of botany students. Gray was grooming Horace Mann Jr. as his replacement, but he died of tuberculosis at the age of 24 in November 1868.