For the table of contents, check at the bottom of this post below the image.
The book is available at Project Gutenberg, Internet Archive, Hathi Trust, and Google Books. There is also a free audiobook at LibriVox. You can get a free Kindle ebook from Amazon too!
2. King Arthur's Court
3. Knights of the Table Round
4. Sir Dinadan the Humorist
5. An Inspiration
6. The Eclipse
7. Merlin's Tower
8. The Boss
9. The Tournament
10. Beginnings of Civilization
11. The Yankee in Search of Adventures
12. Slow Torture
13. Freemen!
14. "Defend Thee, Lord!
15. Sandy's Tale
16. Morgan Le Fay
17. A Royal Banquet
18. In the Queen's Dungeons
19. Knight Errantry as a Trade
20. The Ogre's Castle
21. The Pilgrims
22. The Holy Fountain
23. Restoration of the Fountain
24. A Rival Magician
25. A Competitive Examination
26. The First Newspaper
27. The Yankee and the King Travel Incognito
28. Drilling the King
29. The Small-pox Hut
30. The Tragedy of the Manor-house
31. Marco
32. Dowley's Humiliation
33. Sixth Century Political Economy
34. The Yankee and the King Sold as Slaves
35. A Pitiful Incident
36. An Encounter in the Dark
37. An Awful Predicament
38. Sir Launcelot and Knights to the Rescue
39. The Yankee's Fight With the Knights
40. Three Years Later
41. The Interdict
42. War!
43. The Battle of the Sand-belt
44. A Postscript by Clarence