Awhile back I read a sort of baffling op-ed essay by an environmental writer whose main idea seemed to be that only in the past roughly 25 years, on the initiative of a rising wave of young activists, has any significant move been mounted to address environmental issues. Luckily, I cannot remember the writer’s name or the website where the essay appeared, so no specific person will feel insulted if I point out that this thesis was in the range of dangerously naive.

I say this because even before Bill McKibben’s book “The End of Nature” on environmental crises was published in 1989; before the Clean Water Act in 1972; before the first Earth Day and the establishment of the Environmental Protection Agency in 1970; before the Clean Air Act and Rachel Carson’s “Silent Spring” in 1962, there was plenty of environmental activism. In fact it started — like many of the political, social and economic frictions roiling today — in the 1800s.

To learn, for example, about environmental activism for America’s forests, the writer of the essay mentioned above should read Jeffrey Ryan’s new book, “This Land Was Saved for You and Me.” Ryan outlines the careers of a number of people who recognized in the 19th and 20th centuries that if nothing was done to stop it, America’s forests would be essentially razed by the mid-20th century, leading directly to environmental — and economic — disaster.

As early as 1851, a Maine state report declared that without action, “in a few years our pine timber will become exhausted.” By 1870, more than one-third of the forestland in southwestern and Down East Maine had been basically cleared of trees. These Maine-specific factoids are gleaned from UMaine at Farmington professor Andrew Barton’s book “The Changing Nature of the Maine Woods,” which I dug out in response to Ryan’s history.

The same phenomenon was playing out all over American forests. Among Ryan’s early examples of people who helped curb it are Frederick Law Olmsted, who mounted prodigious efforts to remake landscape architecture into a means for preserving wilderness areas; Franklin B. Hough, who in the 1870s called attention to the need for forest management practices based in science; and Gifford Pinchot, whose vision, energy and political savvy led to the creation of the U.S. Division of Forestry in 1881.

It was an uphill battle because “cut and run” timber harvesters, not to mention mining and other commercial interests contributing to the degradation of forests, held sway with lawmakers. Conflicts also developed among activists about the best approach to save the forests. Theodore Roosevelt, Benton Mackaye, and 1964 Wilderness Act framer Howard Zahniser, among others, all played aggressive roles in the effort to, first, save the forests from destruction, and, second, figure out whether it made more sense to plan and regulate their use through scientific forestry practices, or to preserve them as wilderness. (Ryan provides a short, helpful chapter on “Conservation vs. Preservation.”)

When former Gov. Paul LePage was agitating a few years ago for increased timber harvesting and new mining projects, he was simply continuing a battle between the forces of avarice and the forces of environmental responsibility that started more than 150 years ago. Those who ignore history are doomed to repeat its mistakes. There is a lot to learn from the experience of earlier environmental activists. If it weren’t for Olmsted, Pinchot, Roosevelt, MacKaye, Zahniser, Aldo Leopold, Bob Marshall and others, the crisis the young op-ed writer views as historically neglected would be exponentially worse. “This Land Was Saved for You and Me” shows how some of that worse mess has been staved off.

Jeffrey Ryan, of Portland, is also the author of “Blazing Ahead: Benton MacKaye, Myron Avery, and the Rivalry That Built the Appalachian Trail” and “Appalachian Odyssey: A 28 Year Hike on America’s Trail,” among others. His books are available from local and online book sellers.

Off Radar takes note of poetry and books with Maine connections the first and third Fridays of each month. Dana Wilde is a member of the National Book Critics Circle. Contact him at dwilde.offradar@gmail.com.