Conversation so far:
Where was Rogers Morton born?
Rogers Morton was born in Louisville, Kentucky.
when was Rogers Morton born?
Rogers Morton was born on September 19, 1914.
who were Rogers Morton's parents?
Rogers Morton is the son of David Clark Morton, a physician, and his wife, Mary Harris Ballard Morton, an heiress to a flour milling business.
did Rogers Morton have any siblings?
Rogers Morton was one of three children.
did Rogers Morton go to school?
Rogers Morton received his early education from the Woodberry Forest School near Orange, Virginia, and in 1937 graduated from Yale University.

Question: what did he study?
Self-contained rewrite: what did Rogers Morton study?