The city lies along Tualatin Valley Highway between Forest Grove to the west and Hillsboro to the east.

In 1845, Benjamin Cornelius immigrated to Oregon with his family, traveling with Joseph Meek.

Holladay had been told by Forest Grove and Hillsboro that they would not allow the railroad free right-of-way, so Holladay planned to bypass them, and build Free Orchards into a new city that would become the new county seat of Washington County.

He left his farm and built a new house, a warehouse, and a store in Free Orchards.

Cornelius also built a creamery to process milk, and two sawmills to supply lumber for the growing community.

In 1893, Free Orchards was incorporated and renamed "Cornelius", to honor the man who spent many years helping build the community.

Though Holladay's plan to make Free Orchards into the county seat never materialized, Cornelius survives today as an agricultural town and, increasingly, as a suburb of Portland.

[5] According to the United States Census Bureau, the city has a total area of 2.01 square miles (5.21 km2), all land.

[9] Since 2008, Cornelius has favored the Democratic Party, in line with Washington County as a whole.

Since Barack Obama's 2008 victory, Democrats have consistently won Cornelius by double digits.

It also links Cornelius with the Portland region's light rail system (MAX) in Hillsboro.