In Mary's personal letters....

[LincolnToddFan]

I think many historians and biographers base their speculation about the alleged disruption of the Lincoln's conjugal relations on the fact that they moved into separate rooms shortly after Tad's birth, and that there were no more children.

But as Laurie has pointed out separate rooms were not the exception for married couples of a certain socio-economic background in Victorian times, it was the norm. And even after they moved into separate rooms they always had conjoined quarters, both in Springfield and at the WH.

As for no more children...who knows? I can't answer that one. But just because there were no more children doesn't necessarily mean there was no more intimacy.