Basilica of the National Shrine of the Immaculate Conception up in D.C. The evnet was packed with thousands reportly outside.
A article on the Mass here at At Fortnight closing Mass at National Shrine, overflow crowd prays for religious freedom
The video and text of the Archbishop Chaput Homily here via Rocco at
At Fortnight's Close, "We Belong to God, And Only to God"
Pic links from the Catholic News Service
Matt Bowman that attended has some thoughts.