* The Gift, 1982, Crowell
* The Gift at Christmas, 1983, Crowell
* All-of-a-Kind Family, 1985, Harper & Row
* All-of-a-Kind Baby Sitter, 1986, Harper & Row
* The Secret of Gumbo Grove, 1992, Clarion
* The Night I Stayed Home, 1994, Orchard
* Horace and Morris (but mostly Horace), 1995, Clarion
* Morris and Joan (but mostly Morris), 1996, Clarion
* The Thing at the Foot of the Bed and Other Scary Tales, 1997, Chronicle Books
* Horace and Morris Go Swimming (but mostly Morris), 1998, Clarion
* Horace and Morris Go Camping (but mostly Horace), 2000, Houghton
* I Wish I Were a Dog, 2002, Roaring Brook Press
* Where Does the Brown Bear Go?, 2003, Clarion
* The Thing from Another World (and Other Scary Tales), 2003, Chronicle Books
* Is There Room for a Moose?, 2005, Clarion
* The Thing About Yetis (and Other Scary Tales), 2005, Chronicle Books
* The Thing About Mommies (and Other Stories for Mothers and Sons), 2006, Chronicle Books
* Where's My Teddy?, 2006, Clarion
* Horace and Morris Go to New York (But Mostly Morris), 2007, Clarion
* You're All I Need to Get By, 2008, Schwartz & Wade
* The Thing AboutDaddies (and Other Stories for Fathers and Daughters), 2010, Chronicle Books
* My Little Red Wagon, 2012, Clarion Books
* Happy New Year, Curious George!, 2014, Houghton Mifflin Books for Children
* Goodnight, Curious George!, 2015, Houghton Mifflin Books for Children
* Where are You, Brown Bear?, 2016, Houghton Mifflin Books for Children
* It's Halloween, Curious George!, 2017, Houghton Mifflin Books for Children
* Curious George Goes to the Beach!, 2018, Houghton Mifflin Books for Children
* Curious George's Nutty Adventure, 2019, Houghton Mifflin Books for Children
* Busy Busy Busy, 2020, Roaring Brook Press
* There's a Tiger in the Garden, 2022, Roaring Brook Press
Fiction
* The Shadow Within, 1981, Atheneum
* The Gift-Giver, 1982, Clarion
* Out from the Shadows, 1984, Clarion
* Which Way Freedom?, 1986, Clarion
* The Gift-Giver, 1987, Bantam Doubleday Dell Yearling (juvenile)
* Out of the Shadows, 1987, Bantam Doubleday Dell Yearling (juvenile)
* The Gift, 1992, Bantam Doubleday Dell (juvenile)
* Which Way Freedom, 1992, Bantam Doubleday Dell Yearling (juvenile)
* No Way Out, 1994, Viking
* The Gift, 2000, Bantam Doubleday Dell Anchor (young adult)
* Out from the Shadows, 2001, Bantam Doubleday Dell Anchor (young adult)
* Which Way Freedom, 2001, Bantam Doubleday Dell Anchor (young adult)
* The Trouble with Magnets, 1998, Yearling
* The Big Bike Ride, 2000, Yearling
* The Case of the Missing Dinosaur Bone, 2001, Sterling
* The Case of the Stolen Baseball Cards, 2002, Sterling
* The Case of the Nervous Newscaster, 2003, Sterling
* The Case of the Copier Caper, 2004, Sterling
Nonfiction
* Good-Bye, Vietnam, 1982, Lerner Publications
* The Black Death, 1984, Lerner Publications
* The History of American Indians, 1990, Scholastic
* The Children of Colonial America, 1991, Scholastic
* The Wild West, 1993, Scholastic
* The Pilgrims' First Thanksgiving, 1994, Scholastic
* The Civil War, 1995, Scholastic
* The Women's Suffrage Movement, 1996, Scholastic
* The World War II Home Front, 1997, Scholastic
* The Underground Railroad, 1998, Simon & Schuster
* The New World, 1999, Scholastic
* The New United States, 2000, Scholastic
* The Young United States, 2001, Scholastic
* The Mighty American Revolution, 2002, Scholastic
* The Mighty Age of Discovery, 2003, Scholastic
* The Mighty American West, 2004, Scholastic
* The Mighty Middle Ages, 2005, Scholastic
* The Mighty Roman Empire, 2006, Scholastic
* The Mighty American Civil War, 2007, Scholastic
* The Mighty Ancient Egypt, 2008, Scholastic
* The Mighty Dinosaur Age, 2009, Scholastic
* The Mighty World War II, 2010, Scholastic
* The Mighty Explorers & Discoverers, 2011, Scholastic
* The Mighty Space Era, 2012, Scholastic
* The Oregon Trail, 2015, Scholastic
* Pilgrims, 2017, Scholastic
* Alexander Hamilton, 2020, Scholastic
* Harriet Tubman, 2021, Scholastic
* The Underground Railroad, 2021, Scholastic
Biographies
* Emily Dickinson, 2002, Clarion
* Charles Lindbergh, 2003, Clarion
* Helen Keller, 2004, Clarion
* Eleanor Roosevelt, 2005, Clarion
* George Washington Carver, 2006, Clarion
* Thomas Edison, 2007, Clarion
* Henry Ford, 2008, Clarion
* Amelia Earhart, 2009, Clarion
* Jackie Robinson, 2010, Clarion
* Albert Einstein, 2011, Clarion
* Rosa Parks, 2012, Clarion
Fiction (Under Pseudonym J.L. Marlow)
* The Shadow Brothers #1: Danger at Shadow Canyon, 1990, Archway Books
* The Shadow Brothers #2: The Haunted Swamp, 1990, Archway Books
* The Shadow Brothers #3: Lost in the Everglades, 1990, Archway Books
* The Shadow Brothers #4: The Mysterious Cave, 1990, Archway Books
* The Shadow Brothers #5: The Forbidden Island, 1990, Archway Books
* The Shadow Brothers #6: The Ghost Town, 1991, Archway Books
* The Shadow Brothers #7: The Hidden City, 1991, Archway Books
* The Shadow Brothers #8: The Secret of Shadow Island, 1991, Archway Books
* The Shadow Brothers #9: The Legend of the Golden Warrior, 1991, Archway Books
* The Shadow Brothers #10: The Battle for Shadow Mountain, 1991, Archway Books
* The Shadow Brothers #11: The Return of the Shadow Brothers, 1992, Archway Books
* The Shadow Brothers #12: The Day of the Shadow Brothers, 1992, Archway Books