Ellis has written four books either wholly or partly about Cape Cod history. As well, he has authored numerous comparable articles in regional magazines such as Cape Cod, Cape Cod Life, On the Water, and Coastal Lifestyle: Cape Cod and the Islands. He has lectured on historical matters including a slide presentation on Thoreau’s Cape Cod. Following Thoreau’s keen interest in wildflowers, Ellis has conducted wildflower inventories and led wildflower walks for the local land trust. He has been active in local historical societies and organizations, and he is a member of the Thoreau Society.

Mr. Ellis published A Ruinous and Unhappy War with Algora in 2009. His first book, Mad Jack Percival: Legend of the Old Navy, came out in 2002.

A lifelong resident of Cape Cod, Mr. Ellis is a direct descendant of no fewer than 17 of the passengers on the Mayflower.

But the journal for his 1857 trip, his fourth and last visit to the Cape, although as rich as his earlier journals, has been ignored. Recently, the "Writings of Henry D. Thoreau Project" at the University of California, Santa Barbara, has prepared a meticulous and updated transcript of Thoreau’s journal in general.

Using the Project’s transcription, this book is an edited version of his journal from that 11-day fourth trip. To set the scene and offer background, substantial annotation is provided by the Editor. This book will be a pleasure for a wide range of readers from those who appreciate Thoreau's observations to history buffs and all who appreciate literature, nature and environmental concerns.