[1] Meacham wrote American Lion drawing in part on previously unavailable documents, including letters, diaries, memorabilia, and accounts from Jackson's intimate circle that had been largely privately owned for 175 years.

American Lion is not a full-scale account of Jackson's entire life or political career, but rather focuses on his presidency and his domestic arrangements in the White House.

[8] By contrast, Meacham wrote that Jackson felt the country was "suffering from a crisis of corruption (in) the marshaling of power and influence by a few institutions and interests that sought to profit at the expense of the whole".

[9] Meacham wrote that Jackson's most enduring conviction was that, as President, he was acting selflessly in the interest of the nation and of its mass of citizens, and that his own will was the same as the will of the country.

"[18] As the book recounts, Jackson was not compelled by treaties signed and assurances previously provided to Native Americans; he did not believe that they had title to the land, and he would not tolerate what he felt were competing sovereignties within the nation.

[25] Finally, the book focuses on Emily Donelson's role as White House hostess and de facto First Lady of the United States.

[34][35] It was the third book he wrote, following Franklin and Winston: An Intimate Portrait of an Epic Friendship (2003) and American Gospel: God, the Founding Fathers, and the Making of a Nation (2006).

[2][35][39] Meacham said he was "surprised, delightfully so" by the number of new sources that emerged in the course of his research, which he said "provide hitherto unknown details about a lost world that foreshadowed and shaped our own".

[41] The Merritt letters included new details about Emily Donelson's role in the life of the White House,[39] as well as the fact that John Henry Eaton considered resigning from Jackson's administration in the spring of 1829.

"[38] Meacham was also given access to the private collection of letters and memorabilia held by Scott Ward, a descendant of Andrew Jackson Jr. living in Atlanta.

[41] Other sources for American Lion included unpublished letters and diary entries from the papers of John Quincy Adams and his wife Louisa, as well as letters from British, Dutch, and French diplomatic archives, which provided observations on the political and social scenes of Washington, D.C.[41] Among these was a note from Richard Wellesley, 1st Marquess Wellesley discussing the risk of the union's collapse during the crisis of nullification.

[4] American Lion is not a full-scale account of Jackson's entire life or political career, but rather focuses on his presidency and his domestic arrangements in the White House.

"[48] Ann Robinson of The Oregonian wrote that the book illustrates how Jackson changed the U.S. presidency in ways that continue to resonate in modern times, particularly in his expansive claims for the executive branch's inherent constitutional powers, such as the veto.

[4] Meacham wrote: "In the saga of the Jackson presidency, one marked by both democratic triumphs and racist tragedies, we can see the American character in formation and in action.

"[35] Conversely, Meacham believed one of the triumphs of Jackson's life was that he held together a country which ultimately – albeit belatedly – extended its protections and promises to all.

[56] Prior to the publication of American Lion, Pulitzer Prize-winning author and historian Daniel Feller read the manuscript and fielded questions from Meacham about the work.

[65] In American Lion, Newsweek editor Jon Meacham gives us the most readable single-volume biography ever written of our seventh president, drawing on a trove of previously unpublished correspondence to vividly illuminate the self-made warrior who 'embodied the nation's birth and youth.'

[40] The New York Times literary critic Janet Maslin called it a "carefully analytical biography (which) looks past the theatrics and posturing to the essential elements of Jackson's many showdowns".

[52] Presidential biographer Doris Kearns Goodwin called American Lion "a beautifully written, absolutely riveting story",[1] describing Meacham as "a master storyteller (who) interweaves the lives of Jackson and the members of his inner circle to create a highly original work".

[71] Historian Michael Beschloss called it "a spellbinding, brilliant and irresistible journey (that) shows us how the old hero transformed both the American presidency and the nation he led.

[45] Erik J. Chaput of The Providence Journal called American Lion an "engaging and oftentimes brilliant study" of Jackson, and felt it was at its best during its analysis and discussion of the Petticoat Affair.

However, he expressed surprise that the book so rarely turns to life outside Washington: "The people, for all their centrality to Jackson's administration, are also the most notable omission in Mr. Meacham's account.

"[80] Adera Causey of Chattanooga Times Free Press called Meacham a "solid writer (who) seamlessly explicates complicated political issues", and presents Jackson's story in an approachable format.

However, she said he spent too much time on the Eaton affair and could have devoted more attention to such issues as the handling of Native American land rights, slavery, and the unique roles of church and state.

[81] Alex Beam, columnist for The Boston Globe, was very critical of American Lion, saying he attempted to portray Jackson too positively,[82][83] and "trafficks in treacly legends",[82] and calling the book "laughable" and "piffle".

[83] Beam wrote: "Meacham is a smooth writer and I can't fault him for seeking the shortest possible path to the bank, penning triumphalist, jingoistic hogwash".

[82] An AudioFile review of the American Lion audiobook complimented Richard McGonagle's vocal delivery, which it said improved upon the "sometimes chatty and unabashedly pro-Jackson history" presented in the narrative itself.

[100] When the Pulitzer Prize jury awarded the book in 2009, the judges described it as "an unflinching portrait of a not always admirable democrat but a pivotal president, written with an agile prose that brings the Jackson saga to life".

[102] In December 2015, HBO announced it was working on a six-hour television miniseries based upon the book, also to be called American Lion,[103] starring Sean Penn as Andrew Jackson.

Jacobson optioned the rights for American Lion after reading the book in 2012: "I saw a lot of analogies with what is happening now and felt the story needed to be told.