Murphy was born in South Carolina in 1796; in his early years, he read law in Virginia,[1] and began practicing in Chillicothe, Ohio, in 1818.

[2] Although his excellent oratorical skills made him a sought-after criminal defense lawyer, Murphy was primarily interested in politics.

[5] On April 10, 1843, Murphy received his second appointment: he was to be the fourth chargé d'affaires to the Republic of Texas, to replace Joseph Eve.

A week later, the appointment of Abel P. Upshur as Secretary of State made the annexation of Texas a priority issue for the Tyler administration.

While not directly engaged in negotiations, Murphy did exchange correspondence with President Houston of Texas,[9] and took part in secret preparations for the passage of the Tyler-Texas treaty.

Although they had been agreed upon and carried out by President Tyler after he signed the treaty in April 1844,[10] this significantly jeopardized Murphy's confirmation process, and led to the resignation of Treasury Secretary John Canfield Spencer.