As an author, public historian, and educator, Tim strives to find creative ways to engage diverse audiences with history and to demonstrate the relevance of the past.

In his writing, Tim draws from his experiences working as a public historian for over twenty-five years. His career has included positions at the Smithsonian National Portrait Gallery, the Smithsonian National Museum of American History, the Smithsonian National Air and Space Museum, the Missouri Historical Society, and the Colonial Williamsburg Foundation in Virginia. During the Lewis and Clark Bicentennial 2004-06, Tim helped develop the national exhibition which traveled the country. He is listed among the history field’s “most engaging, innovative, and entrepreneurial leaders,” and profiled in the book Leadership Matters (Rowman and Littlefield Press, 2014). His co-authored book for museum practitioners, The Museum Educator's Manual, is now in a second edition. (Rowman and Littlefield Press, 2017) Tim’s career memoir, A Grizzly in the Mail and Other Adventures in American History (University of Nebraska Press, 2014), highlights some of the fun projects he has worked on.

More recently Tim had been writing history nonfiction for ages 10-14. His latest book, The World Turned Upside Down: The Yorktown Victory That Won America's Independence, was published in April 2022. His book First Flight Around the World (Abrams Books for Young Readers, 2015) was a finalist for the 2016 YALSA Excellence in Nonfiction award. He followed that with Milestones of Flight (Abrams Books for Young Readers, 2016), featuring fascinating stories about thirty iconic artifacts in the National Air and Space Museum collection (yes, the Wright Flyer, the SR-71 and the Space Shuttle Discovery are in it, along with the Starship Enterprise studio model!)

Tim’s books incorporate a variety of primary source materials and teach students and educators the historical thinking process — critical thinking, multiple perspectives, historical context and weighing sources. He strives to write books that teachers will want to use in the classroom.

COMING IN 2026 - Tim's new book about George Washington, a perfect read for America's 250th birthday year. This book is officially sanctioned by George Washington's Mount Vernon and while it targets young readers (ages 10-14), like all of Tim's book it will be a fun read for adults, too. Watch for more information about it in the coming year.