Whitman did indeed have much to do with this building. As the website explains:

"From 1861 to 1863 the top floor of the Patent Office served as a hospital for soldiers. Poet Walt Whitman tended the soldiers there. 'It was a strange, solemn sight,' he wrote, 'the glass (model) cases, the beds, the forms lying there, the gallery above, and the marble pavement under foot.' "In 1865, Whitman secured a clerkship in the Indian Affairs Bureau in the building and was working there at the time of Lincoln's second inaugural ball: 'I have been up to look at the dance and supper rooms....What a different scene they presented to my [earlier] view, filled with a crowded mass of the worst wounded of the war. Tonight, beautiful women, perfumes, the violins' sweetness, the polka and the waltz, then the amputation, the blue face, the groan, the glassy eye of the dying.' Whitman was dismissed from his position at Indian Affairs when Interior Secretary James Harlan discovered that he was the author of Leaves of Grass, which Harlan had labeled an 'indecent book.'"

So now they're trying to make this up to his memory by renaming the street!