March was born in Dallas, Texas; the daughter of Laura Len (née Irwin) and John Abraham "Abe" March IV. She has German, Irish and English ancestry. She attended Highland Park High School, the same high school Angie Harmon (of the original Law & Order) attended. March was a sophomore when Harmon was a senior. She began performing in plays in high school. In 1996 she graduated from the School of Speech (now School of Communication) at Northwestern University, where she majored in Theater and Hispanic Studies. After graduating, she landed her first professional acting role (in her very first audition) as Helena in A Midsummer Night's Dream in Chicago, where she continued to pursue her stage career.

In 1999, March made her Broadway debut in the highly acclaimed production of Arthur Miller's Death of a Salesman, opposite Brian Dennehy. Her other career highlights include roles on the television series Early Edition and in the TV movie Since You’ve Been Gone.

Her bigg