Keegan Law Firm, LLC Conveniently located in beautiful downtown Greenville, SC on Main Street, Keegan Law Firm, LLC is a legal practice founded on the performance excellence that is the goal of the Malcolm Baldrige National Quality Award. Whether your needs require estate planning, commercial or residential real estate transactions or starting a new business, the team at Keegan Law Firm, LLC will be happy to assist you. Mark S. Keegan has been an attorney since 1977 and focuses on Residential & Commercial Real Estate Transactions & Development Business Formation, Mergers and Acquisitions Estate Planning, Wills & Trusts