text:  Most music historians date the writing of " The <unk> Blues " to Lead <unk> 's June 1937 trip to Washington , DC , when he was invited by the <unk> Alan <unk> to record for the Library of Congress 's folk music collection . On the first night Lead <unk> and his wife Martha spent in the city , they encountered racially <unk> Jim Crow laws similar to those found in their native Louisiana : most hotels refused to rent rooms to African Americans and the few that would were either full or refused to serve him because he was with a white man ( <unk> ) . <unk> , in some versions of the story described as an unnamed " white friend " , offered to let the couple stay for the night in his apartment near the Supreme Court Building . The next morning , Lead <unk> <unk> to <unk> arguing with his <unk> about the presence of a black man , with the <unk> threatening to call the police . 
  