New Hampshire Law Firm Gallagher, Callahan & Gartrell - New Hampshire Attorneys, New Hampshire Law Firm Gallagher, Callahan & Gartrell, PC, provides legal services in four core industries - financial services and banking, insurance and insurance defense, energy and utilities, and real estate development and land use - Ranked Best Law Firms Tier One metropolitan law firm in many practices by Best Lawyers / U.S. News for 2020 - serving specialty industries and private clients in New Hampshire from its law offices in Concord, NH 03301 03301.