war. >>chris: and then there's the study. >> that's where truman had his oval office during the renovation of the white house when he lived here. >>chris: in 1950, two puerto rican nationalists try to shoot their way into blair house and kill the president. >> president truman continued to take his daily walks. two quick shooting white house guards were wounded in the - - that marks the assault. >>chris: jimmy carter gave blair house a new role. every president-elect sent has been the night before his inauguration and what's called the principal sweet. with two separate bedrooms. but the main role of blair house is what it's been for 76 years, to extend the nation's hospitality the presidential guests. no matter how short thenotice . >> the house is always ready no matter what. if one showed up this morning or tomorrow, we are always ready for a visitor.