Van Buren led the Free Soil Party's presidential ticket and appealed to many anti-slavery Democrats, possibly contributing to the victory of Whig nominee Zachary Taylor.

[3] He joined the Freemasons, an increasingly popular fraternal organization in that period, being initiated as an Entered Apprentice in what was later American Union Lodge No.1 at Marietta on December 5, 1803.

On July 16, 1812, a British force consisting of the 41st Regiment of Foot, 60 men of the Canadian Militia and a number of Indians were posted near Fort Malden.

Cass and Miller send word to General William Hull, requesting permission to attack Fort Malden and hold it until reinforcements arrived.

However, Hull, an indecisive officer, was unsupportive and refused to agree to their request, which led Cass and Miller to withdraw their men back to American lines.

[5] On July 19, 1812, Colonel Duncan McArthur with a reconnaissance force combined with 150 Ohio infantry troops under Cass were near the bridge leading to Fort Malden.

[6] On July 28, 1812, Colonel Cass conducted a hit-and-run attack at the Rivière aux Canards driving back a band of Native Americans.

As a reward for his military service, Cass was appointed Governor of the Michigan Territory by President James Madison on October 29, 1813, serving until 1831.

In 1817, Cass was one of the two commissioners (along with Duncan McArthur), who negotiated the Treaty of Fort Meigs, which was signed on September 29 with several Native American tribes of the region, under which they ceded large amounts of territory to the United States.

In 1820, Cass led an expedition to the northwestern part of Michigan Territory, in the Great Lakes region in today's northern Minnesota.

[9] Despite his later claims to the contrary, as territorial governor, Cass is known to have owned at least one slave, a household servant, as evidenced by 1818 correspondence between him and Alexander Macomb.

[9] In 1830, Cass published an article in the North American Review that passionately argued that Indians were "inherently inferior" to whites, and incapable of being civilized and thus should be removed from the eastern United States.

On August 1, 1831, Cass resigned as governor of the Michigan Territory to take the post of Secretary of War under President Andrew Jackson, a position he would hold until 1836.

[12] Cass was a leading supporter of the doctrine of popular sovereignty, which held that the (white male) American citizens who lived in a territory should decide whether to permit slavery there.

On March 6, 1857, President James Buchanan appointed Cass to serve as Secretary of State as a consolation prize for his previous presidential runs.

Although retaining incumbent Secretary of State William L. Marcy was considered the best option by many, Buchanan made it clear that he did not want to keep anyone from the Pierce Administration.

Buchanan, weighing many of the other options for Secretary of State, considered that Cass was the best choice to avoid political infighting and sectional tensions.

Buchanan wrote a flattering letter offering him the post of Secretary of State, commenting that he was remarkably active and energetic for his advanced age.

Most assumed Cass was a temporary Secretary of State until a younger, more fit man could be found, however, he ultimately served for all but the final four months of Buchanan's administration.

As expected, the aged Cass largely delegated major decision-making to subordinates, but eagerly signed his name on papers and dispatches penned by them.

[8] While sympathetic to American filibusters in Central America, he was instrumental in having Commodore Hiram Paulding removed from command for his landing of Marines in Nicaragua and compelling the extradition of William Walker to the United States.