after 1857 when Brazilian historian Francisco Adolfo de Varnhagen wrote that everything in the Soderini letter was true. Other historians followed in support of Vespucci including John Fiske and Henry Harrisse. In 1924, Alberto Magnaghi published the results of his exhaustive review of Vespucci's writings and relevant cartography. He denied Vespucci's authorship of the 1503 Mundus Novus and the 1505 Letter to Soderini, the only two texts published during his lifetime. He suggested that the Soderini letter was not written by Vespucci, but was cobbled together by unscrupulous Florentine publishers who combined several accounts – some from Vespucci, others from elsewhere. Magnaghi determined that the manuscript letters were authentic and based on them he was the first to propose that only the second and third voyages were true, and the first and fourth voyages (only found in the Soderini letter) were fabrications. While Magnaghi has been one of the chief proponents of a two-voyage narrative, Roberto Levellier was an influential Argentinian historian who endorsed the authenticity of all Vespucci's letters and proposed the most extensive itinerary for his four voyages. Other modern historians and popular writers have taken varying positions on Vespucci's letters and voyages, espousing two, three, or four voyages and supporting or denying the authenticity of his two printed letters. Most authors believe that the three manuscript letters are authentic while the first voyage as described in the Soderini letter draws the most criticism and disbelief. A two-voyage thesis was accepted and popularized by Frederick J. Pohl (1944), and rejected by Germán Arciniegas (1955), who posited that all four voyages were truthful. Luciano Formisiano (1992) also rejects the Magnaghi thesis (acknowledging that publishers probably tampered with Vespucci's writings) and declares all four voyages genuine, but differs from Arciniegas in details (particularly the first voyage). Samuel Morison (1974) flatly rejected the first voyage but was noncommittal about the two published letters. Felipe Fernández-Armesto (2007) calls the authenticity question "inconclusive" and hypothesizes that the first voyage was probably another version of the second; the third is unassailable, and the fourth is probably true. Legacy Vespucci's historical importance may rest more with his letters (whether or not he wrote them all) than his discoveries. Burckhardt cites the naming of America after him as an example of the immense role of the Italian literature of the time in determining historical memory. Within a few years of the publication of his two letters,