He graduated from Rhode Island College (now Brown University) in 1802, was admitted to the bar in 1805, and, after two years' study abroad in Poitiers and London,[3][4] practiced law at Providence (1807-1812) and at New York City (1812-1827).

Aided by Justice Joseph Story, his reports were known for their comprehensive notes and summaries of the arguments presented by each side.

He also took part in important cases, and was the sole associate of Daniel Webster in that which settled the limits of the state and federal legislation in reference to bankruptcy and insolvency.

[5] He served until 1835, displaying skill in the settlement of the sound dues that were imposed by Denmark on the vessels of all countries, and obtained modifications of the quarantine regulations.

On March 25, 1844, he signed a treaty with Germany, for which he received high commendation from President Tyler and John C. Calhoun, the secretary of state.

[3] Other issues Wheaton dealt with during his diplomatic career were Scheldt dues, the tolls on the Elbe, and the rights of naturalized citizens.

[4] In 1846 Wheaton was requested to resign as Prussian minister by the new president, Polk, who needed his place for another appointment.