In 1987, Henderson entered the University of North Carolina School of
Law, where he earned membership on the North Carolina Law Review.  After graduating in 1990 with honors, Henderson returned to Southern California.

Upon entering the California bar, Henderson practiced for 3½ years at O'Melveny & Myers, focusing mainly on corporate, financing and real estate transactional law.  He left in 1994 to litigate at Hall and Associates (later Hall & Henderson LLP).  There, his practice involved prosecuting state and federal civil trials, writs, motions and appeals, and arguing before the Supreme Court of the United States.  During these years, Henderson gained experience representing many non-profit organizations that oppose environmentally harmful development, including Natural Resources Defense Council, Sierra Club, Environmental Defense Fund, Heal the Bay, Santa Monica Baykeeper, and Friends of Ballona Wetlands, in addition to representing Los Angeles World Airports concerning land use issues.

In 2002, Henderson aimed his career back toward his pre-law vocation of real estate development and construction, when he joined KB Home as its counsel and Director, Government and Public Affairs.  Henderson left in 2005 to serve as the Executive Vice President and General Counsel of the Building Industry Association of Southern California, Inc. (BIASC) and General Counsel of its litigation affiliate, Building Industry Legal Defense Foundation (BILD).  In these roles, Henderson covered the waterfront of legal issues that affect Southern California's developers and builders.  Henderson served at BIASC and BILD for almost nine years, until he left in 2013 to start The Henderson Law Firm.