Florence crowded in early March?

Less so than April through October.

Depends on the day of the week. We were there for 5 nights early March last year and while we pretty much had the run of the place during the week--except for the students and their visiting parents--on Saturday and Sunday (and to a certain extent Friday) it was fairly overrun around the attractions.

Accademia is a small museum, can be done in an hour, but is very cool. David and the Slaves of Prisoners, both by Michelangelo, are spectacular. I would get my tickets in advance (they give you an appointment), and hopefully the one day you're in Florence is a weekday. There will still be lines to get in but it shouldn't be too bad during the week.

If you don't want to stand in line then book your timed entry on the official Accademia website. THere's no right or wrong answer and no real way to predict the crowds on a particular date.

Went passed the Accademia (in February several years ago), mid-afternoon, and there was no line so I went in (had been before) and there weren't many people at all. I've read that even when it's very busy in the morning, it's often quiet in the late afternoon.