Tony,
Others will chime in, but the Harpers are very interesting. I only have one pdf copy (1900) and have looked at the 1901. USGA appears to only have those two Harpers in their archives. Not sure of the total number of Harpers' golf annuals.
Maybe Bob Crosby can chime in.
Or send an email to USGA and ask them about Harpers. They do respond fairly quickly.
The Harpers 1900 version had a wonderful state by state list of the existing courses with some description of each, like this for one this site favs.
....NEWPORT GOLF CLUB (A.)—Three miles from Newport Station, on the N. Y., N. H. & H. Railroad. Organized July, 1893. Incorporated 1895. Entrance fee, $100. Annual dues, $40. Visitors pay $1.50 per day. Membership, 125. The cightecn-hole course was laid out by W. F. Davis in 1896.
The lengths of the holes are: 1, 185; 2, 375; 3, 360; 4, 1:10; 5, 420; 6, 350; 7, 400; 8, 375; 9, 150; 10, 215; 11, 365; 12, 172; T3, 188; 14, 340; 15, 485; 16, 300; 17, 330; 18, 325. The amateur record, 79, is held by A. M. Coats. The professional record is 75, by W. F. Davis. The club possesses a very handsome clubhouse, and this and the other property of the club are worth $175,000. President, Buchanan Winthrop; vice-president, Wm, R. Travers; secretary and treasurer, R. I. Gammell, Providence, R. I.; chairman of house
committee, Royal Phelps Carroll, Newport, R. I. Governing committee: B. Winthrop, W. R. Travers, R. P. Carroll, A. M. Coats, J. C. Gray, Geo. P. AVetmore, Victor Sorchan, Arthur Kemp, F. P. Sands and R. I. Gammell. Greenkeeper, Yule
Harpers also listed a complete summary of the championships, printing the USGA rules, etc.
The Harpers have some marvelous photographs of the old courses in between the text for each courses. Most descriptions are like that for Newport.
Another annual summary publication is the American Annual Golf Guide. The USGA appears to have copies from 1916 to 1931. This guide covers the many competitions (those outside USGA) very extensively, with articles, photos, etc.
This guide doesn't appear to cover the courses very much at all, except for the occasional list. But, I have only looked at 3 or 4 of these.