Frederick Dickinson of the School of Arts and Sciences spoke about the history of opposition to limiting non-white immigration. The racial equality clause in the Treaty of Versailles, for example, was “one of the first attempts to establish ... the unprecedented principle of free and open migration,” he said.
https://www.npr.org/sections/codeswitch/2019/08/11/742293305/a-century-later-the-treaty-of-versailles-and-its-rejection-of-racial-equality NPR