Final answer:
Napoleon and Thomas Jefferson adopted Neoclassical style for building commissions to embody values of rationality, classical virtue, and patriotism. They referenced ancient Greek and Roman monuments, symbolizing enlightened governance and democracy. The style was meant to inspire with classical antiquity's ideals.
Step-by-step explanation:
Leaders like Napoleon and Thomas Jefferson adopted the Neoclassical style for their building commissions because they wanted to convey values of rationality, virtue, and patriotism, which were prominent during the French Revolution. This architectural style referenced monuments of classical antiquity, especially Greek and Roman, and was a response against the Rococo and Baroque excesses. Neoclassicism symbolized a return to the order and harmony seen in the works of ancient civilizations.
The architectural monuments of the past that were referenced include those of the Greek and Roman empires. Excavations such as those at Pompeii and Herculaneum, as well as measured drawings from the journeys of individuals like James "Athenian" Stuart and Nicholas Revett, informed the style's revival. Buildings that exemplified this style include the US Capitol and structures that emulated the Greek Revival, expressing admiration for Greek democracy and Roman Republican virtues.
With the choice of Neoclassical style, leaders hoped to project enlightened governance and democratic principles. They also sought to promote a sense of cultural refinement and strength through association with classical antiquity, aiming to inspire their citizens with the ideals of heroism, democracy, and cultural achievement as seen in works like Jacques-Louis David's "Oath of the Horatii" and iconic monuments such as the US Capitol building.