Are college fraternities like Delta Upsilon part of the Illuminati?

Regan was a TKE

But no, on the whole i don't think so.

If president Garfield was a member more than likely the fraternity was founded by high masons. There are many ways to tell. Either by the founding members, whoever created the rituals, the rituals themselves, and magazines publications and symbolism used that may be templar-ish or rosicrucian.