Novel: 'Mei's father, a track worker, swung the hammer and drove the golden spike himself.' History: 'On May 10, 1869, railroad officials joined the two lines at Promontory Summit, Utah, with a ceremonial golden spike.' What did the novelist change?

Novel: 'By dusk the brothers had flown four times, and Tomas carried the wing back down the sand each time.' History: 'On December 17, 1903, the Wright brothers made four flights at Kitty Hawk; the longest lasted 59 seconds.' What did the novelist add?

Novel: 'In one night the fire swallowed the whole city, and by morning nothing stood.' History: 'The Great Chicago Fire burned from October 8 to October 10, 1871, destroying much of the city.' How does the novel differ from the account?

Novel: 'Pierre paddled west with the expedition in spring and was home in St. Louis before the first snow.' History: 'The expedition left St. Louis in May 1804, reached the Pacific in November 1805, and returned in September 1806.' What is compressed?

Novel: 'The doctor chalked an H on Anya's shoulder. Her sister squeezed her hand and whispered that it would wash off.' History: 'At Ellis Island, doctors chalked letters on arrivals' coats to mark them for medical examination.' Which detail is invented?

Novel: 'The canal was Sam's whole world: the mule's ears, the towrope, the smell of the water.' History: 'The Erie Canal, opened in 1825, ran 363 miles and cut the cost of shipping goods across New York.' Why tell the story through one boy and a mule?

Novel: 'For twenty years the riders carried the mail, and Jesse's father rode nearly all of them.' History: 'The Pony Express carried mail between Missouri and California from April 1860 to October 1861, when the telegraph was finished.' What is altered?

Novel: 'All three of them stood in the dust together, boots sinking, while the world watched.' History: 'On July 20, 1969, two Apollo 11 astronauts landed on the Moon while the third stayed in orbit in the command module.' What does the novel change?

Novel: 'The sky went brown at noon. Ruth's mother nailed wet sheets over the windows and they ate in the dark.' History: 'On April 14, 1935, a huge dust storm swept the southern Plains; papers called it Black Sunday.' Which detail is the novel's alone?

Novel: 'Ned watched from the wharf as the men emptied the one ship and the water turned brown.' History: 'On December 16, 1773, colonists boarded three ships in Boston Harbor and threw 342 chests of tea into the water.' What did the novelist alter?

Novel: 'The ship struck, and within minutes the deck stood on end and the lights went out.' History: 'The Titanic hit an iceberg late on April 14, 1912, and sank early the next morning, more than two hours after the collision.' How does the novel differ?

Novel: 'Within a week at the river, Cal had two jars of gold and bought his mother a house.' History: 'Gold was found at Sutter's Mill in 1848, but most who rushed to California in 1849 never struck it rich.' Which impression does the account contradict?

Novel: 'They walked all through that one long winter, and by spring the buses were theirs to ride anywhere.' History: 'The Montgomery bus boycott began on December 5, 1955, and lasted 381 days, ending in December 1956.' What has the novelist compressed?

Novel: 'Nora's grandmother said she saw the great statue the day she arrived in 1878, and cried.' History: 'The Statue of Liberty, a gift from France, was dedicated in New York Harbor on October 28, 1886.' What is historically impossible here?

Novel: 'The Larsens signed for their hundred and sixty acres in spring and owned them outright by harvest.' History: 'The Homestead Act of 1862 offered 160 acres of public land to settlers who farmed it for five years.' What does the novel leave out?

Novel: 'Rosa and her friend Etta ran for the ninth-floor door and found it locked.' History: 'A fire at the Triangle Shirtwaist Factory in New York on March 25, 1911, killed 146 workers.' Why might the novelist follow two named workers?

Novel: 'The whistle blew at four, and Ada had an hour to reach the hill before the water came.' History: 'On May 31, 1889, the South Fork Dam failed and the flood destroyed Johnstown, Pennsylvania, killing more than 2,200 people.' What does the novel add?

Novel: 'Eli's hands shook on the key as he tapped out the words, and the answer came back at once.' History: 'On May 24, 1844, the first message on the Washington-to-Baltimore telegraph line read, What hath God wrought.' Which element is invented?

Novel: 'Otto's foreman said the new line would build a car in ten minutes, and it did.' History: 'In 1913, a moving assembly line at a Michigan auto plant cut the time to build a chassis from over twelve hours to about ninety minutes.' What is altered?

Novel: 'Tess stood on the Kansas platform holding her brother's hand, and they were chosen together.' History: 'From 1854 to 1929, charities sent about 200,000 children by train from eastern cities to families in the Midwest.' What does the novel do?