For members of the Church of Jesus Christ of Latter Day Saints, traveling to certain parts of the United States offers many more sights to visit. Certain locations like Salt Lake City, Nauvoo Illinois or even Palmyra, New York during the pageant time could be vacations all their own. I've always combined any church history sights with other typical vacation sights in those areas. Occasionally I'll meet someone who is doing a full on church history tour only visiting church sights following the pioneer route. To me, you could easily get church history overload with this so I don't recommend it.
LDS Historic Sights
Kirtland Sights (Kirtland Ohio)
San Diego Mormon Battalion Historic Site
Utah LDS Historic Sights
Growing up in the Seattle suburbs, the only church buildings I was accustomed to were the standard cookie-cutter designs built by the LDS church since the 1950's. When I moved to Utah, I noticed all kinds of old and unique buildings the small towns throughout the region. I began researching some of these only to learn there were many old buildings scattered in the larger cities throughout Salt Lake, Davis and Utah counties. I have yet to find any resource listing all the pre-1940 structures. My interest is mostly the tabernacles and chapels but other old buildings include old bishops storehouses, relief society centers and assembly halls...the precursor for the "gyms" in our chapels.
Others to come:
Wyoming LDS Historic Sights
Other LDS Stuff
New York LDS Historic Sights
Missouri LDS Historic Sights
Illinois LDS Historic Sights
Iowa & Nebraska LDS Historic Sights