I recently finished going through the Golfers' Guide of 1908, and was surprised by two things in its course listing. First, the number of clubs that did not have a professional, and second, the scarcity of 18 holers in the country at that time. The listing in the guide seemingly only addresses private clubs, with a number of prominent hotel, resort and public courses not making it in. In addition, there are a number of courses for which the number of holes isn't noted.
I've noted below by state the 18 hole courses included which total 130 of the 800 course listed in the Guide (for comparison, a 1902 guide notes 99 18 hole course).
If anyone has any others to add to the list please chime in.
Edit: Going to annotate the list with any additions marked in italics.
AL
CC of Montgomery
CA
Annandale GC
Claremont GC
Coronado GC - noted in a 1902 Guide as having 18 holes, reduced to 9 in 1907
San Francisco G&CC l/k/a Ingleside GC
Los Angeles CC
Oakland GC - gave up its links in 1905
San Rafael GC - noted in Harpers 1901 with 18 holes
Santa Cruz CC - earlier club, probably gone by 1908
CO
Denver CC
Lakewood CC f/k/a The Colorado GC of Denver
Town and Gown GC
CT
Hartford GC
New Haven CC
New Haven GC - club disbanded in 1908 with course carried on as public and reduced from 18 to 9 holes
Pine Orchard CC
Sound Beach G&CC
Wadawanuck GC
DE
Wilmington CC
FL
Florida CC
Palm Beach GC
Tampa Bay Hotel GC - noted in Harpers 1901 with 18 holes
GA
Augusta CC
East Lake CC f/k/a Atlanta Athletic Club
IA
G&CC of Des Moines
IL
Auburn Park Club - went out of existence in 1908
Beverly CC
Calument CC
Chicago GC
Evanston GC
Exmoor CC
Flossmoor CC
Glen View Club
Hinsdale GC
Jackson Park GC
Midlothian CC
Onwentsia Club
Ravisloe CC
Rock Island Arsenal Club
Westward Ho CC
Wheaton GC
Windsor Park GC
IN
Highland GC
Ligonier GC - noted in Harpers 1901 with 18 holes
LA
Audobon GC
MA
Brae Burn CC
C. B. Cory Private Course - noted in the 1902 Guide with 18 holes
Cottage City GC - noted in the 1902 Guide with 18 holes
Essex County Club - noted in the 1902 Guide with 18 holes
Myopia Hunt Club
Nantucket GC
Commonwealth CC a/k/a Newton Commonwealth GC
Oakley CC
CC of Springfield
Stockbridge GC
The Country Club a/k/a CC of Brookline
Wollaston GC
Woodland CC
MD
Baltimore CC
Chevy Chase CC
Columbia GC
MI
Detroit (CC of) - noted in the 1902 Guide with 18 holes
Detroit GC
Harbor Point CC
Kent CC
Lake Harbor Club
Lebanon GC
Seymour GC - noted in the 1899 Guide with 18 holes
Wequetonsing GC - noted in the 1902 Guide with 18 holes
MN
Minikahda Club
Town and Country Club
MO
Evanston GC
Glen Echo CC
Kansas City CC
Normandie GC
Westwood CC
NC
Cameron GC
Pinehurst CC #1
Pinehurst CC #2
NE
Happy Hollow Club
Overland CC
Omaha CC
Omaha Field Club
NH
Mount Pleasant GC - noted in the 1902 Guide with 18 holes
Waumbeck GC - noted in the 1902 Guide with 18 holes
NJ
Atlantic City CC
Baltusrol GC
Canoe Brook CC
Deal G&CC
Englewood GC
Essex County CC
Forest Hill Field Club
Hollywood GC
CC of Lakewood
Montclair GC
Morris County GC
Newark Athletic Club - out of existence by 1905
North Jersey CC
Pine Forest GC f/k/a GC of Lakewood - noted in the 1902 Guide with 18 holes
Plainfield CC
Princeton GC - noted in the 1902 Guide with 18 holes
Seabright GC - noted in the 1902 Guide with 18 holes
Upper Montclair CC
Yountakah CC
NY
Apawamis Club - noted in the 1902 Guide with 18 holes
Ardsley GC - noted in the 1902 Guide with 18 holes
Century GC
Cobble Hill GC
Columbia CC
Crescent Athletic Club - noted in the 1902 Guide with 18 holes, shortened to 9 holes in 1908
Dunwoodie GC
Brooklyn - Forest Park GC
Fox Hills GC
Garden City GC
Genessee GC
CC of Buffalo
Harbour Hill GC - noted in the 1902 Guide with 18 holes, may have disbanded by 1908
Hotel Champlain GC - noted in the 1902 Guide with 18 holes
Inwood CC
Knollwood CC
Maidstone Club
Malone GC
Mohawk GC
Monticello GC - noted in the 1902 Guide with 18 holes
Nassau CC
New York GC (a club that played at Van Cortlandt Park)
Oakland GC
Park Club of Buffalo
Powelton Club - noted in the 1902 Guide with 18 holes, but only 9 holes open
Richmond County CC
Rochester (CC of) - noted in the 1902 Guide with 18 holes
Rockaway Hunting Club - noted in the 1902 Guide with 18 holes, shortened to 9 holes by 1908
Scarsdale GC - noted in the 1902 Guide with 18 holes
Shinnecock Hills GC - noted in the 1902 Guide with 18 holes
St. Andrews GC
Stevens House GC - noted in the 1902 Guide with 18 holes
Tuxedo GC - noted in the 1902 Guide with 18 holes
Westbrook GC
Wykagyl CC
Yahnundasis GC
OH
Cincinnati GC - noted in the 1902 Guide with 18 holes
Elberton CC
Euclid Club
OR
Waverly CC
PA
Allegheny CC
Bala GC
Huntingdon Valley CC
Delaware County Field Club l/k/a Llanerch CC
Merion Cricket Club
Mount Airy CC - noted in the 1902 Guide with 18 holes
Oakmont CC
Philadelphia CC
Philadelphia Cricket Club
Pike Run CC
Pittsburg GC l/k/a Schenley Park Municipal GC
CC of Scranton
Springhaven Club
St. Davids GC
Whitemarsh Valley CC
RI
Misquamicut GC
Newport CC - noted in the 1902 Guide with 18 holes
Point Judith CC - noted in Harpers 1901 with 18 holes
SC
Palmetto GC
Pine Forest Inn GC - noted in the 1902 Guide with 18 holes
TN
Memphis CC
Nashville G&CC l/k/a Richland CC
UT
The Country Club, Salt Lake City - noted in Harpers 1900 with 18 holes
VT
Ekwanok CC
Shelburne Farms Links - noted in the 1902 Guide with 18 holes
WA
Seattle G&CC
Tacoma C&GC
WI
Kenosha CC
Lake Geneva CC - noted in the 1902 Guide with 18 holes