I found out that the English language pack for Moodle is "British" English, which is why "enrollment" is spelled "enrolment". I just installed the U.S. English language pack and reset everyone's language preference to that.
Question: Is there a value for adding other language packs (e.g. Spanish, Korean, etc.)? This only affects Moodle's buttons, not the content of any courses, so perhaps this can wait till we have a course developed in a non-English language. Your thoughts?