As a Marylander, I played, as birthright, lacrosse starting at about age 5 and effectively ending at Cornell almost two decades later. (FYI, goalie.) I guess the crowds watching me (& my team) maxed out at a thousand or so for a Princeton game at Princeton. Moreover, the reach of the sport at the time was little more than the mid-Atlantic states, and New England.
Not only has the playing of the sport grown like Topsy (my 20-year-old informs me there's a club team in Durango CO), but so have the interested parties. I must admit I was almost driven to tears when I read yesterday that this weekend's NCAA final, in which Virginia beat Massachusetts 15-7, was witnessed by the largest LAX crowd ever—47,062. (In Philadelphia.)