In 1803, the United States bought 828,000 acres west of the Mississippi River from France for $15 million, and 16 years later Moses Bates established Hannibal, Missouri. John Clemens, a Tennessee native whose general store in Florida, Missouri, was failing, moved his family, including four-year-old Sam, to Hannibal in 1839 and built this house on land purchased by his cousin. After the family fell on hard times in 1846, they moved across the street to live with the Grant family above their pharmacy, then returned to the house after John died in 1847 when Sam was 11 years old. In 1851, Sam's sister Pamela married and moved to St. Louis; two years later Jane Clemens and her sons Orion and Henry moved to Iowa, while 17-year-old Sam left for solo adventures in St. Louis and beyond. The house later served as rental property until 1911, when it was slated for demolition, but George A. Mahan bought it, repaired it, and gave it to the city for public use on May 15, 1912, two years after Twain's death. The museum building beside the Boyhood Home and the stone wall around the courtyard were completed in 1937 by the Works Project Administration, with the wall serving as a firewall between the property and a lumberyard. The home was fully restored and stabilized between 1990 and 1991, including reconstruction of two rear rooms removed around 1885, and, opened to the public in 1912, it became one of America's earliest historic homes, later being listed on the National Register of Historic Places and designated a National Historic Landmark.