The Oldest Methodist Church in Northern Illinois:
In 1829 the first regularly appointed Methodist minister arrived in Galena. By 1832 a plain frame church was erected on Bench Street, but was lost to fire in 1838. A new building was built in 1841, and by 1856 the congregation had grown so that yet another new brick and stone church needed to be built. The present church was dedicated in 1857.

2 First settled in 1833, Batavia had a population of 3,018 by 1870 (Gustafson and Schielke, 59). In 1867, when many states were actively encouraging emigration, the Kane County Gazetteer promoted Batavia:

Possibly misidentified, this location my actually be North Hall.  North Hall was constructed in 1865, to be used, in part, as a University Chapel. The original recommendation, made by Governor Samuel Kirkwood, requested funds for a chemistry laboratory, chapel and astronomical observatory, and over the years, North Hall, the two-and-a-half-story, red-brick classic, certainly became a multi-use facility.

I found references to three Methodist Churches in Ottawa, IL but found no mention of dates for their structures.  The First United Methodist Church at 100 West Jefferson Street, Ottawa, IL 61350 is closest to downtown Ottawa