Here is a nifty little site that gives you the bestselling books of each year of the entire 20th Century. It was fascinating for me to review those books I had read that were popular with other generations of Americans. It also gave me a bunch of ideas about what I would like to read from those long-ago years -- if I can find a copy. It certainly reveals how fickle is popular opinion about literature; that is, so many of the books that American readers embraced in one generation were completely ignored by the next.
Anyhow, you might like to peruse the lists and see what books from our past made their way to your eyes too. Below you'll find one exercise -- I looked through the first three decades of the 20th Century and found those books that I've read. Here they are with the titles that I would recommend to others put in bold print.
From 1900: #5. Eben Holden by Irving Bacheller (also #5 in 1901) and #8. Richard Carvel by Winston Churchill. (Not the Winston Churchill you're thinking of.)
1902: #1. The Virginian by Owen Wister (also #5 in 1903) and #7. The Hound of the Baskervilles by Arthur Conan Doyle.
1905: #4. The Clansman by Thomas Dixon Jr.
1906: #6. The Jungle by Upton Sinclair.
1913: #8. Pollyanna by Eleanor H. Porter (also #2 in 1914).
1914: #3. The Desert of Wheat by Zane Grey. Also in the Non-Fiction category, I've read #1. The Education of Henry Adams by Henry Adams.
1920 Non-Fiction: #3. Roosevelt's Letters to His Children, Joseph B. Bishop, editor. (That would be Teddy Roosevelt, by the way.)
1921 Non-Fiction: #1. The Outline of History by H. G. Wells (also #1 in 1922 and #5 in 1923).
1925 Non-Fiction: #3. When We Were Very Young by A. A. Milne and #4. The Man Nobody Knows by Bruce Barton (also #1 in 1926).
1926 Non-Fiction: (besides Barton's) 8. The Story of Philosophy by Will Durant (also #1 in 1927).
1927 Non-Fiction: (besides Durant's) #3. Revolt in the Desert by T. E. Lawrence
1928: #1. The Bridge of San Luis Rey by Thornton Wilder and #4. The Greene Murder Case by S. S. Van Dine. Also wrongly put in the Non-Fiction category (it is a play) is #5. Strange Interlude by Eugene O'Neill
1929: # 1. All Quiet on the Western Front by Erich Maria Remarque and #4. The Bishop Murder Case by S. S. Van Dine. Also, at #8 in the Non-Fiction category (again, wrongly put) is the narrative poem, John Brown's Body by Stephen Vincent Benét.