After an extensive period of study, during which he sporadically contributed to academic journals, Prescott specialized in late Renaissance Spain and the early Spanish Empire.

During his lifetime, he was upheld as one of the greatest living American intellectuals, and knew personally many of the leading political figures of the day, in both the United States and Britain.

[2][3] Historians admire Prescott for his exhaustive, careful, and systematic use of archives, his accurate recreation of sequences of events, his balanced judgments and his lively writing style.

[9] As a young man, Prescott frequented the Boston Athenæum, which at the time held the 10,000-volume private library of John Quincy Adams, who was on a diplomatic mission to Russia.

[14][15][16] Prescott's eyesight degenerated after being hit in the eye with a crust of bread during a food fight as a student, and it remained weak and unstable throughout the rest of his life.

[20] Prescott first used a noctograph while staying with Adams; the tool became a permanent feature of his life, allowing him to write independently in spite of his impaired eyesight.

He visited Hampton Court Palace with future American president John Quincy Adams, at the time a diplomat in London, where they saw the Raphael Cartoons.

Da Ponte published the criticisms as an appendix to his translation of Dodley's Economy of Human life, which resulted in Prescott noticing them rather late.

[31] His acquaintance Pascual de Gayangos y Arce helped him construct a sizable personal library of historical books and manuscripts concerning the subject.

[34] Eventually George Ticknor, who was by then in charge of the department of modern literature at Harvard University, found James L. English, who worked with Prescott until 1831.

[36] In spring 1828, Prescott visited Washington, where he and Ticknor dined with John Quincy Adams at the White House, and saw Congress in session.

[41] Despite this personal tragedy, and his own continued ill health, Prescott had gathered sufficient material to begin drafting the History in October 1829.

[43] Prescott also encountered Elogia de la Réina Doña Isabel, by his Spanish contemporary Diego Clemencín, which helped shape his views concerning the monarchs' political roles.

The History of Ferdinand and Isabella was published on Christmas Day, 1837 by the American Stationery Company, Boston, with a print run of 500 copies.

To the surprise of Prescott and the publisher, the book sold very well—the original print run was insufficient to adequately supply Boston's bookshops, let alone the whole nation's.

In particular, he considered Edward King's theory that the pre-Columbian civilizations were non-indigenous to be fallacious, although he was greatly indebted to him for his anthology of Aztec codices in the Antiquities of Mexico.

He was also entertained by John Y. Mason, the former United States Secretary of the Navy, who informed him that a copy of Prescott's Conquest of Mexico had been placed in the library of every fighting ship.

[89] Shortly after the publication of the Conquest of Peru, Prescott turned his mind to writing a history of Philip II of Spain, which he had been contemplating for several years.

However, Lembke, who as a diplomat had been expelled from Spain, made the acquaintance of two wealthy Parisian scholars, Mignet and Ternaux-Compans, who offered him access to their manuscript collections.

[93] Furthermore, de Gayangos assisted greatly by locating important documents in the British Museum and in the collection of the bibliomaniac Thomas Phillipps, who owned around 60,000 manuscripts.

He also borrowed several manuscripts from the archives in Brussels, having received letters from the respected Belgian diplomat Sylvain Van de Weyer in London.

[94] By the summer of 1848, Prescott had over 300 works on the subject at his disposal, but he continued to have serious problems with his eyesight; an examination by an oculist confirmed that there was untreatable damage to his retina.

Two days later, he traveled to Brussels, where he stayed in Coudenberg, the site of a residence of the Holy Roman Emperor Charles V, returning to London on July 29.

Previously uninterested in politics (although he had predicted the Whig victory in 1840,[120]) Prescott supported and voted for the Republican John C. Frémont in the 1856 Presidential election.

[130] He was buried with his parents in St. Paul's Church, and his funeral was attended by representatives, among others, of Harvard University, the American Academy of Arts and Sciences and the Essex Institute.

[131] Prescott's work has remained popular and influential to the present day, and his meticulous use of sources, bibliographical citations and critical notes was unprecedented among American historians.

David Levin has argued that the Conquest shows "inadequate attention to detail" and remains a broad and general account of events.

[137] However, it is generally thought that the work was the authoritative account until the 20th century, and that Prescott used a broader range of source material than any previous writer on the subject.

[142] There is a popular misconception that Prescott was completely blind, which seems to have stemmed from a misunderstanding of his comment in the preface to The Conquest of Mexico, in which he stated, "Nor have I ever corrected, or even read, my own original draft".

[145] C. Harvey Gardiner's 1969 work[146] is considered the definitive critical biography of Prescott, taking into account a wide range of unpublished documents that were unavailable to earlier biographers.