Lincoln Curtain?

[richard petersen]

I subscribe to Bloomberg Business Week. In an article it mentions a building in Dallas Tx that has been renovated. "Step inside the building and you might think you are in a museum, with Rodin and Maillol sculptures in the hallways... and a piece of curtain on display that Abraham Lincoln is believed to have grabbed after being shot"
Has anyone read that Lincoln grabbed a curtain?
Where would this curtain have been located in the box?[/b]