Oliver Walker and Laird Dunlop founded Walker & Dunlop in 1937. The Washington, D.C.-based firm opened its doors as one of the first companies to use Federal Housing Administration (FHA) insurance to make single-family home loans. By the end of World War II, Walker & Dunlop was pioneering the first uses of Taft-Hartley funds for mortgage and real estate investment.

Throughout the decades, the firm continued to be an industry leader and in 1971 arranged the first off-balance sheet financing for the United States government at the U.S. Geological headquarters in Reston, Virginia.

In 1974, Oliver Walker's son, Mallory, became president and chief executive officer of Walker & Dunlop. Under the younger Mr. Walker's leadership, the firm continued to innovate and in 1988 launched one of the first companies under Fannie Mae's Delegated Underwriting and Servicing (DUS™) program. The entity, formally known as Green Park Financial, now operating as Walker & Dunlop, is one of the largest Fannie Mae DUS™ lenders in the nation.

In the 1990s, the firm became a major lender to the real estate investment trust (REIT) industry, using cross collateral and substitution of assets in revolving credit structures for major REITs including Charles E. Smith Residential, United Dominion Realty Trust and Walden Residential Properties.

In 2003, Mallory Walker's son, William, took on the management of the company and today serves as the president and chief executive officer.

In early 2009, Walker & Dunlop merged with Column Guaranteed LLC. Walker & Dunlop now offers multifamily lending for Fannie Mae, Freddie Mac and HUD.

Now with over 120 employees across the nation and in its third generation of Walker management, Walker & Dunlop remains the firm of choice for discerning commercial and multifamily real estate investors, owners and developers.