I have read that around 23% of the
USA sailboat builders went out of business since 2004-2005. I believe 2011 is the latest year for reliable figures, but the total number of cruising sailboats built in the
USA was only 622: 30-35 feet = 215; 36-45 feet = 348; 46+ feet = 59.
More information here. I suspect there is a list of all
boat manufacturers someplace, but not sure where.
If you go here, and search on sailboat manufacturers you only get 13, and I'm not sure all of them make boats in North America.