Editing Jefferson Davis (section)

===Secretary of War===
[[File:Jefferson Davis 1853 daguerreotype-restored.png|thumb|[[Daguerreotype]] of [[United States Secretary of War]] Davis (1853)|alt=Portrait of Davis looking forward]]

In March 1853, President Franklin Pierce named Davis his [[United States Secretary of War|Secretary of War]].{{sfn|Wallner|2007|pp=5–6}} He championed a [[transcontinental railroad]] to the Pacific Ocean, arguing it was needed for national defense,{{sfn|Wallner|2007|p=52}} and was entrusted with overseeing the [[Pacific Railroad Surveys]] to determine which of four possible routes was the best.{{sfn|Wallner|2007|pp=40–41}} He promoted the [[Gadsden Purchase]] of today's southern [[Arizona]] from Mexico, partly because he preferred a southern route for the new railroad. The Pierce administration agreed and the land was purchased in December 1853.{{sfn|Waite|2016|pp=541–542}} He presented the surveys' findings in 1855, but they failed to clarify the best route and sectional problems prevented any choice being made.{{sfn|Wallner|2007|p=181}} Davis also argued for the acquisition of Cuba from Spain, seeing it as an opportunity to add the island, a strategic military location and potential slave state.{{sfnm|Cooper|2000|1p=265|Eaton|1977|2p=101}} He suggested that the size of the regular army was too small and that its salaries were too meagre. Congress agreed and authorized four new regiments and increased its pay scale.{{sfn|Cooper|2000|p=251}} He ended the manufacture of smoothbore muskets and shifted production to rifles, working to develop the tactics that accompany them.{{sfn|Cooper|2000|pp=254–255}} He oversaw the building of public works in Washington D.C., including the initial construction of the [[Washington Aqueduct]].{{sfn|Davis|1991|pp=236–237}}

Davis assisted in the passage of the [[Kansas-Nebraska Act]] in 1854 by allowing President Pierce to endorse it before it came up for a vote.{{sfnm|Cooper|2000|1pp=266–268|Davis|1991|2pp=248–249|Wallner|2007|3pp=95–97}} This bill, which created [[Kansas Territory|Kansas]] and [[Nebraska Territory|Nebraska]] territories, repealed the [[Missouri Compromise]]'s limits on slavery and left the decision about a territory's slaveholding status to [[Popular sovereignty#1850s|popular sovereignty]], which allowed the territory's residents to decide.{{sfn|Potter|1976|pp=158–161}} The passage of this bill led to the demise of the Whig party, which had tried to limit expansion of slavery in the territories. It also contributed to the rise of the [[Republican Party (United States)#19th century|Republican Party]] and the increase of [[Bloody Kansas|civil violence in Kansas]].{{sfn|Eaton|1977|pp=88–89}}

The Democratic nomination for the 1856 presidential election went to [[James Buchanan]].{{sfn|Davis|1991|pp=250–251}} Knowing his term was over when the Pierce administration ended in 1857, Davis ran for the Senate once more and re-entered it on March 4, 1857.{{sfn|Cooper|2000|pp=274–276}} In the same month, the [[United States Supreme Court]] decided the [[Dred Scott v. Sanford|Dred Scott case]], which ruled that slavery could not be barred from any territory.{{sfn|Cooper|2000|p=284}}