Complex sentence: In March 1929 came the first public event held by Bahá'ís was attempted in Binghamton-a Race Amity Conference-though it became mired in controversy, about the fact it was sponsored by Bahá'ís, but not wanting to make it the leading point of the meeting.
Split into simpler sentences: In March 1929 came the first public event held by Bahá'ís was attempted in Binghamton-a Race Amity Conference-though it became mired in controversy. There appeared to be controversy that it was Bahá'ís holding it, but not wanting to make it the leading point of the meeting.