| 1 | Theo | Northam | A writer/journalist. A PhD candidate in art history. |
| | Clancy | | Theo's dog. |
| | Jess | | The osteology prep lab manager at a museum in Maryland. |
| | Milo | | Jess's dead dog. |
| | Maisy | | Jess's assistant. |
| | Horace | Wallis | The guy from Affiliates. |
| | Jarret | Lewis | The racehorse trainer's son. |
| | Elisha | Warfield | Harry's boss. A horse lover and breeder. |
| | Alice | Carneal | One of Dr. Warfield's horses. |
| | Harry | Lewis | Jarret's father. A racehorse trainer. |
| | Robert | Burbridge | Harry's former employee. |
| | Boston | | The race horsing champ. |
| | Mary Barr | Clay | Dr. Warfield's granddaughter. |
| | Annie | | Dr. Warfield's maid. |
| | Cassius | Clay | Mary's father. A real estate mogul. |
| | Abiona | | Theo's mother. |
| | Barry | | Theo's father. |
| | Lior | | Theo's editor. |
| | Thomas | Scott | The man who studied horse anatomy. Dr. Warfield's painter. |
| | Richard | Singleton | Marse's horse. |
| | Willa | Viley | Harry's former employee. |
| | Edward | Troye | The Swiss painter. |
| | Glacier | | One of Dr. Warfield's horses. |
| | Tom | Custler | The marine mammal biologist. |
| | Eric | | Hank's owner. |
| | Hank | | Eric's dog. |
| | Daniel | | Theo's best friend. |
| | Frederick | Douglas | An essayist. |
| | Madame | Mentelle | Mary's teacher. |
| | Rex | | One of Dr. Warfield's horses. |
| | Onyx | | One of Dr. Warfield's horses. |
| | Charles | | Colonel Johnson's horse trainer. |
| | Beth | Lewis | The Warfield's housekeeper. Harry's 2nd wife. |
| | Catherine | Morgan | A researcher. Jess's visitor. |
| | Darley | | Dr. Warfield's prize horse. |
| | Mary Jane | Warfield | Dr. Warfield's daughter. Cash Clay's wife. |
| | Henry | Clay | The greatest breeder in Kentucky. Cash's brother. |
| | Anne | Warfield | Mary Jane's sister. |
| | John | Porters | Harry's favorite jockey. |
| | Lolu | | Cash's mistress. |
| | Royal | Eclipse | A famous English racehorse. Cyrena's horse partner. |
| | James | Mullen | An army photographer. |
| | Glencoe | | The great stallion. |
| | Timon | | One of the old roans. |
| | Garret | Davis | One of the racehorses. |
| | Richard | Ten Broeck | A race course owner. |
| | Louis | Smith | Dr. Warfield's colleague. |
| | Grey | Eagle | One of the great horses. |
| | Ester | | The Warfield's cook. |
| | Ryolite | | Cash's chief mount. |
| | Marquis | | Cash's cavalry-trained horse. |
| | Jeremy | Raines | The conservator. |
| | Mr. | Pryor | A horse trainer. |
| | Colonel | Bingaman | Viley and Ten Broeck's friend. |
| | William | Johnson | A barbershop owner. |
| | Ben | | Pryor's driver. |
| | Zack | | One of Pryor's assistants. |
| | Abe | | One of Pryor's assistants. |
| | Samuel | Gossin | The farm manager. |
| | Gem | | Jarret's new companion. |
| | Cato | | Gem's colleague. |
| | Ira | | Gem's colleague. |
| | Old | Gem | Gem's father. A widower. |
| | Henry (2) | | Pryor's headman. |
| | Jack | | Gem's uncle. |
| | Eveline | | Jack's wife. |
| | Jackson | Pollock | An American painter and major figure in abstract expressionist. |
| | Peggy | Guggenheim | An art collector. |
| | Lee | Krasner | Jackson's wife. |
| | Makela | | A curator. |
| | Martha | Jackson | An American art dealer and gallery owner. |
| | Clem | Greenberg | One of Pollock's first champions. |
| | Hofmann | | A painter. Martha's friend. |
| | Marc | Chagall | A famous painter. |
| | Jacques | Garmond | Ten Broeck's chief of staff. |
| | Sallie | Waters | Louis Smith's racehorse. |
| | Arrow | | One of Boston's sons. Ten Broeck's horse. |
| | Henri | Meichon | Lexington's jockey. |
| | Annie | | Martha's housekeeper. |
| | Charlie | | Annie's brother. |
| | Cyrena | | A 3-time champion in the national hunt team. Martha's mother. |
| | Howard | Kelogg | Cyrena's husband. |
| | Welsh | Cobs | One of Martha's horses. |
| | Fashion | Eclipse | Martha's house. Royal Eclipse's half-sister. |
| | Julien | | A painter. Thomas Scott's new companion. |
| | Anel | De Pujol | An art school owner. Julien's master. |
| | Jacques-Louis | David | The great classicist. De Pujol's professor. |
| | Little | Flea | One of the horses Viley leased. |
| | Millard | Filmore | The President. |
| | Lecompte | | One of Boston's sons. Lexington's race opponent. |
| | Duncan | Kenner | A baron. Arrow's owner. |
| | Abe | Hawkins | Arrow's jockey. |
| | Highlander | | A 4-year-old champion. One of Lexington's opponents. |
| | Gilbert | Watson | Highlander's jockey. Lexington's new jockey. |
| | Thomas Jefferson | Wells | Lecompte's owner. |
| | Hark | | Well's horse trainer. |
| | John | | Lecompte's jockey. |
| | William | Stuart | Ten Broeck's friend. |
| | Mike | | Theo's friend. |
| | Hakeem | | Theo's friend. |
| | Robert | Alexander | An estate owner in Scotland. |
| | Napoleon | Belland | The newspaper boy. |
| | Nebula | | One of Lexington's daughters. |
| | Novice | | One of Lexington's daughters. |
| | Dan | Swigert | Mr. Alexander's farm manager. |
| | May | | Mr. Alexander's laundress and seamstress. |
| | Ethelburt | Dudley | A surgeon. Scott's regiment commander. |
| | Parson | Gunn | A school owner. |
| | John Singer | Sargent | A portrait painter. |
| | Paul | Mellon | A library owner. |
| | Mary | Mellon | Paul's 1st wife. |
| | Bunny | | Mary's friends. |
| | Mill | Reef | One of Paul's racehorses. |
| | Arts | | One of Paul's racehorses. |
| | Letters | | One of Paul's racehorses. |
| | General | Grant | Cincinnati's owner. |
| | Cincinnati | | The great mount. |
| | Mr. | Lincoln | The current President. |
| | William | Quantrill | The guerilla captain. |
| | Sayers | | Viley's friend. A judge. |
| | Finetta | | Sayers's wife. |
| | Nanny | Butler | One of Jarret's horses. |
| | John | Hunt-Morgan | The leader of Morgan Raiders. |
| | Justine | Treadwell | A writer from Washington Post. |
| | Sanders | Bruce | A union army colonel. |
| | Eohippus | | The dawn horse. |
