This structure - the Memorial Building - houses a log cabin at the site of Lincoln's birth. The log cabin isn't actually Lincoln's but is rather considered "symbolic". In fact, the National Park Service employee inside told us that wood in the cabin was dated in the past few years to the 1840's. It's size and shape, I suppose, is representative of the one where Lincoln was born.
The front of the building is quite impressive.
A plaque (one of two) notes the group that raised funds for the project. The Lincoln Farm Association was formed in 1906 to preserve Lincoln's birthplace. The group raised more than $350,000 from about 100,000 citizens to build the memorial to house the cabin. Theodore Roosevelt laid the cornerstone; William Taft attended the 1909 dedication.