Complex sentence: Meanwhile, H.K. Ellyson continued in his church-related activities, as he acknowledged in 1883, although African-American members had left to form their own church in 1846 (also called Second Baptist Church, but on Idlewood Avenue).
Split into simpler sentences: Meanwhile, H.K. Ellyson continued in his church-related activities, as he acknowledged in 1883. However, African-American members had left to form their own church in 1846 (also called Second Baptist Church, but on Idlewood Avenue).