[1][2] McCarty was born in 1679, the son of wealthy Irish immigrants who had arrived in Virginia four years' prior.
[3][4] He studied law and in 1702 at the age of 23, he began working as an assistant at the Westmoreland County Court.
In addition to representing the area in the House of Burgesses, McCarty held other positions within Westmoreland County.
The session of 1715, over which McCarty presided, has been regarded by historians as a period of intense political infighting between Governor Alexander Spotswood and the House of Burgesses.
[9] McCarty remained as an active member of the House for several subsequent sessions, including serving as chairman on the committee on propositions and grievances.