Marcia is an ancient Roman name which derives from Mars, the god of war. It was used byDdante in the Inferno and later by Thomas Hardy and others.
Marcia enjoyed a brief run of popularity in the mid-twentieth century--it was a Top 100 name from 1943 to 1955-- then was replaced by Marcy and Marci. Now all three are in limbo, replaced by the newer Marley or the more vintage Marcella. An alternate spelling of Marcia is Marsha.