Daniel H. Lownsdale was born in Mason County, Kentucky, in 1803. He married Ruth Overfield in 1826, and they moved west to Indiana. The couple had three children before Ruth Lownsdale died in 1830. Daniel Lownsdale lived in Europe from 1842 to 1844. In 1845, he emigrated to Oregon, where he purchased part of Amos King's land claim at what would become the city of Portland, and established a tannery. He served in the Oregon provisional legislature in 1846.

In 1849, Lownsdale purchased an additional land claim from Francis Pettygrove for $5,000. He then resurveyed the land and began selling lots. In 1852, he donated a strip of his land claim to the City of Portland to be used as a firebreak. Parts of this strip of land would later become the South Park Blocks and the North Park Blocks; the central section was never formally deeded to the city, and would later be sold for development.

Lownsdale scouted the route for a road from the Tualatin Valley to Portland, and successfully lobbied the Oregon territorial legislature for a charter to construct what would become the Great Plank Road, which was constructed in 1856. He also served as the federal postal agent for Oregon under U.S. President Millard Fillmore. Lownsdale's later years included a legal dispute with investors led by Josiah Parrish over Lownsdale's 1840s claim to land, levees, and docks on the west side of the Willamette River, with the investors claiming that the land on the banks of the river was public. In 1858, the U.S. Supreme Court ruled that because there were no laws governing land in Oregon before 1850, no one could claim title to the disputed lands.

Lownsdale remarried in 1850 to Nancy Gillihan, a widow; the couple would have two children. Lownsdale died in 1862.

Sources: Corning, Howard McKinley, editor, "Dictionary of Oregon History," 2nd edition, 1989; "Daniel Lownsdale (1803-1862)," by Chet Orloff, Oregon Encyclopedia, https://www.oregonencyclopedia.org/articles/lownsdale-daniel/#.YqeEQKjMIuU..