[105]
Secretary of War Jefferson Davis, at Pierce's request, led surveys by the Corps of Topographical Engineers of possible transcontinental railroad routes throughout the country. The Democratic Party had long rejected federal appropriations for internal improvements, but Davis felt that such a project could be justified as a Constitutional national security objective. Davis also deployed the Army Corps of Engineers to supervise construction projects in the District of Columbia, including the expansion of the United States Capitol and building of the Washington Monument.[106]

Foreign and military affairs
The Pierce administration aligned with the expansionist Young America movement, with Marcy leading the charge as Secretary of State. Marcy sought to present to the world a distinctively American, republican image. He issued a circular recommending that U.S. diplomats wear "the simple dress of an American citizen" instead of the elaborate diplomatic uniforms worn in the courts of Europe, and that they only hire American citizens to work in consulates.[107][108] Marcy received international praise for his 73-page letter defending Austrian refugee Martin Koszta, who had been captured abroad in mid-1853 by the Austrian government despite his intention to become a U.S. citizen.