I may be hypersensitive, but I found it a little sad that the theme of the puzzle today, two days after the bombing in Boston, was security. But I won't dwell on it. I did that yesterday.
There was some good cluing in this one. Right off, the oh-so-common AMA was given a clue that made me need two crosses to fill it in, 1A: Org. founded by Dr. Nathan Smith Davis. I liked that change, and I also liked the tricky 13A: Minnesota neighbor (MANITOBA), because even though, after going through the neighboring U.S. states and figuring out that it had to be a province, I still needed a couple letters because I couldn't think of the answer right away.
On the down side, and there was a lot of downside, I find answers like ESTOP, REPACK, and ADRIP, kind of lame. I think AMUCK (1D: In a frenzy) is less common than "amok," and MAPLE is less common as a 2D: Bat wood, than "ash," isn't it? Is "Happy Days" still on anywhere in syndication? "Mrs. C." was an easy answer, of course, and I suppose a lot of solvers are my age or older, but jeez, it seems old even to me!
p.s. Huygens, were you somewhat annoyed that 69A: Primes, e.g.:Abbr. are here reduced to just being NOS?