Benjamin Franklin (January 17, 1706 [O.S. January 6, 1705] – April 17, 1790) was one of the Founding Fathers of the United States. A noted polymath, Franklin was a leading author, printer, political theorist, politician, postmaster, scientist, musician, inventor, satirist, civic activist, statesman, and diplomat. As a scientist, he was a major figure in the American Enlightenment and the history of physics for his discoveries and theories regarding electricity. He invented the lightning rod, bifocals, the Franklin stove, a carriage odometer, and the glass 'armonica'. He formed both the first public lending library in America and the first fire department in Pennsylvania.

Franklin earned the title of "The First American" for his early and indefatigable campaigning for colonial unity; as an author and spokesman in London for several colonies, then as the first United States Ambassador to France, he exemplified the emerging American nation. Franklin was foundational in defining the American ethos as a marriage of the practical and democratic values of thrift, hard work, education, community spirit, self-governing institutions, and opposition to authoritarianism both political and religious, with the scientific and tolerant values of the Enlightenment. In the words of historian Henry Steele Commager, "In a Franklin could be merged the virtues of Puritanism without its defects, the illumination of the Enlightenment without its heat." To Walter Isaacson, this makes Franklin "the most accomplished American of his age and the most influential in inventing the type of society America would become."

Friedrich Wilhelm Heinrich Alexander Freiherr von Humboldt ( listen (help·info) September 14, 1769 – May 6, 1859) was a German geographer, naturalist and explorer, and the younger brother of the Prussian minister, philosopher and linguist Wilhelm von Humboldt (1767–1835). Humboldt's quantitative work on botanical geography laid the foundation for the field of biogeography.

Between 1799 and 1804, Humboldt travelled extensively in Latin America, exploring and describing it for the first time in a manner generally considered to be a modern scientific point of view. His description of the journey was written up and published in an enormous set of volumes over 21 years. He was one of the first to propose that the lands bordering the Atlantic Ocean were once joined (South America and Africa in particular). Later, his five-volume work, Kosmos (1845), attempted to unify the various branches of scientific knowledge. Humboldt supported and worked with other scientists, including Joseph-Louis Gay-Lussac, Justus von Liebig, Louis Agassiz, Matthew Fontaine Maury and, most notably, Aimé Bonpland, with whom he conducted much of his scientific exploration.

Marco Polo (ⁱ/ˈmɑrkoʊ ˈpoʊloʊ/; Italian pronunciation: [ˈmarko ˈpɔːlo]; c. 1254 – January 9, 1324) was a Venetian merchant traveler from the Venetian Republic whose travels are recorded in Il Milione, a book which did much to introduce Europeans to Central Asia and China. He learned about trading whilst his father and uncle, Niccolò and Maffeo, travelled through Asia and apparently met Kublai Khan. In 1269, they returned to Venice to meet Marco for the first time. The three of them embarked on an epic journey to Asia, returning after 24 years to find Venice at war with Genoa; Marco was imprisoned, and dictated his stories to a cellmate. He was released in 1299, became a wealthy merchant, married and had three children. He died in 1324, and was buried in San Lorenzo.

Their pioneering journey inspired Christopher Columbus and others. Marco Polo's other legacies include Venice Marco Polo Airport, the Marco Polo sheep, and several books and films. He also had an influence on European cartography, leading to the introduction of the Fra Mauro map.