Raised in rural Upstate New York, Briggs studied law in western Massachusetts, where his civic involvement and successful legal practice preceded statewide political activity.

Although he sought to avoid the contentious issue of slavery, he protested South Carolina policy allowing the imprisonment of free African Americans.

He supported capital punishment, notably refusing to commute the death sentence of John White Webster for the murder of George Parkman.

[4] At the age of 14, during the Second Great Awakening, which was especially strong in Upstate New York, Briggs experienced a conversion experience and joined the Baptist faith.

He spoke at revival meetings of his experience, drawing appreciative applause from the crowds, according to Hiland Hall, who came to know Briggs at that time and who became a lifelong friend and political associate.

[5] His faith informed his personal behavior: he remained committed to religious ideals, for instance objecting to Congressional sessions that stretched into Sunday and abstaining from alcohol consumption.

[21] Briggs and Hall were both instrumental in drafting and gaining passage of the Post Office Act of 1836, which included substantive accounting reforms in the wake of financial mismanagement by Postmaster General William Taylor Barry.

He formed the Congressional Temperance Society in 1833, sitting on its executive committee; at an 1836 temperance convention at Saratoga Springs, New York, he advocated the taking of total abstinence pledges as a way to bring more people away from the evils of alcohol,[6] and notably prepared such a pledge for Kentucky Representative Thomas F. Marshall on the floor of the House of Representatives.

Samuel Hoar and his daughter Elizabeth were unsuccessful in changing South Carolina policy, and after protests against what was perceived as Yankee interference in Southern affairs, were advised to leave the state for their own safety.

Briggs' argument was used in the 1849 trial of Washington Goode, a black mariner accused of killing a rival for the affections of a lady.

The case against Goode was essentially circumstantial, but the jury heeded the district attorney's call for assertive punishment of "crimes of violence" and convicted him.

[34] There were calls for Briggs to commute Goode's capital sentence, but he refused, writing "A pardon here would tend toward the utter subversion of the law.

"[35] Not long after the Goode case came the sensational trial of Professor John White Webster in the murder of George Parkman, a crime that took place at the Harvard Medical School in November 1849.

[36][37] Furthermore, Massachusetts Supreme Judicial Court Chief Justice Lemuel Shaw was widely criticized for bias in the instructions he gave to the jury.

[39] He refused however, stating that the evidence in the case was clear (especially after Webster gave a confession), and that there was no reason to doubt that the court had acted with due and proper diligence.

[18] In 1849, Briggs failed to secure a majority in the popular vote because of the rise in power of the Free Soil Party, but the Whig legislature returned him to office.

[45] In 1861 Briggs was appointed by President Abraham Lincoln to a diplomatic mission to the South American Granadine Confederation (roughly present-day Colombia and Panama).