My wife and I had the opportunity to visit this place during our honeymoon. The house is kept in the most likely shape it was during the time of the Church's organization. It is amazing how small it is as compared to homes nowadays. there is a beautiful chapel on the grounds also that has a history of its own. It is interesting to not how many things took place there:
1. Translation of the Book of Mormon
2. Three Witnesses received their witness of the plates
3. Testimonies of the three and eight witnesses signed in home
4. Official organization of the Church
5. First Sacrament passed and blessed in this Dispensation
6. First Priesthood ordinations (First / Second Elders of the Church
7. 20 sections of the D&C were received
8. First three General Conferences of the Church held
If you would like more information:
https://www.hillcumorah.org/whitmer.asp
Just to clarify, the house is actually a replica and it was built in 1980 and is just an example of the types of homes that were built at the time the Whitmers moved to New York. It is extremely small, I was very surprised also that so many important events within the LDS history took place there.