The Ladd Estate Company was incorporated in Portland, Oregon, in 1908, to manage properties that William Sargent Ladd (1826-1893) had owned. The properties had previously been managed by Ladd & Tilton Bank, and the founding of the Ladd Estate Company was in part to avoid scrutiny required by the 1907 Oregon Banking Act. Although the Ladd & Tilton Bank and the Ladd Estate Company were legally separate entities, William M. Ladd was president of both, and other figures were also involved with both firms. The Ladd Estate Company sold the 462-acre Hazel Fern Farm to the Laurelhurst Company in 1909. The firm developed Ladd's Addition, and platted and developed the Westmoreland, Eastmoreland, and Dunthorpe neighborhoods of Portland. In 1923, the firm took the role of marketing agent for the Oregon Iron & Steel Company, which had shifted to the real estate business.

William M. Ladd resigned from the Ladd Estate Company in 1926 due to ill health. That same year, Paul C. Murphy and Frederick H. Strong purchased the entire holdings of the Ladd Estate Company and the Oregon Iron & Steel Company. Murphy and Strong soon divested themselves of all but the properties in the Dunthorpe neighborhood and in Lake Oswego. Strong served as president until 1930, when Murphy bought out Strong's interest and became president. Later, Murphy's son, Paul F. Murphy, directed the company. Although it was inactive, it remained a registered corporation until October 15, 2001.

Source: "Ladd Estate Company" by Marylou Colver, Oregon Encyclopedia, https://www.oregonencyclopedia.org/articles/ladd_estate_company/