After graduating from Milton, Patrick went on to Harvard, the first in his family to attend college. He received his degree, with honors, in 1978 and spent a post-graduate year working on a United Nations youth training project in the Darfur region of Sudan. He returned to Cambridge to attend Harvard Law School in the fall of 1979.
Following law school, Patrick served as a law clerk to a federal appellate judge before joining the NAACP Legal Defense and Education Fund. In 1986, he joined the Boston law firm of Hill & Barlow and was named partner in 1990, at the age of 34.
In 1994, President Clinton appointed Patrick Assistant Attorney General for Civil Rights, the nation's top civil rights post. During his tenure, Patrick led the largest criminal investigation prior to September 11th, coordinating state, local and federal agencies to investigate church burnings throughout the South in the mid-1990s.
Patrick returned to private practice in 1997 with the Boston firm of Day, Berry & Howard. That same year, he was appointed by a federal district court to serve as the first chairperson of Texaco's Equality and Fairness Task Force. Patrick was hired by Texaco in 1999 to serve as Vice President and General Counsel leading the company’s global legal affairs. In 2000, Patrick joined The Coca-Cola Company as Executive Vice President and General Counsel. He was elected to the additional role of Corporate Secretary in 2002, and served as part of the company’s senior leadership team as a member of the Executive Committee.