Born in Vermont, William Sargent Ladd (1826-1893) came West during the California Gold Rush and settled in Portland in 1851. He prospered as a merchant, established the Ladd and Tilton Bank, and invested in real estate, mainly on the east side of the Willamette River. He was elected mayor in 1854 and was prominent in every aspect of Portland business activity. In 1891 he decided to subdivide his 126-acre farm on Portland's east side. Inspired by Pierre L'Enfant's plan for Washington, D.C., Ladd designed the plat based on a diagonal street system surrounding a central park. Also included were four diamond-shaped rose gardens located on the points of a compass. Ladd's Addition was considerd a radical departure from the common grid pattern of the expanding city.
In 1909, Park Superintendent Emanuel Mische designed a formal landscape plan for the gardens in Ladd's Addition. He planted camellias, perennials, and a lawn area in the central circle and numerous rose varieties in the four diamonds, creating a stunning stained glass effect. Today the gardens feature over 3,000 roses of sixty varieties that were popular in the early 20th century.