During one eight-month period beginning on January 7, 1907, Seattle annexes six nearby incorporated towns and an unincorporated portion of King County, nearly doubling the land area of Seattle. Competition between Seattle and Tacoma to be the dominant city on Puget Sound with the largest population in part motivated this rash of additions to the city.
All of the towns annexed had a city council and mayor. To join Seattle, a petition of at least 20 percent of the town's voters was presented to their respective councils, which were then required to call for an election to vote on dissolving the town and annexing to Seattle. If the vote was favorable and the City of Seattle approved, the town would be annexed.
Following is a list of the towns with their size and the official date of their annexation to Seattle.
- Southeast Seattle (5.73 sq. miles) January 7, 1907
- Ravenna (0.62 sq. miles) January 15, 1907
- South Park (0.87 sq. miles) May 3, 1907
- Columbia (1.12 sq. miles) May 3, 1907
- Ballard (3.71 sq. miles) May 29, 1907
- West Seattle (16.34 sq. miles) July 24, 1907
A 3.62-square-mile area of the Rainier Beach, not an incorporated town, petitioned the King County Commissioners, and after an affirmative vote, was annexed to Seattle on September 12, 1907.
In all, the area of Seattle nearly doubled, increasing from 35.09 square miles to 67.10 square miles. The city continued to annex adjoining areas and by 1954 had increased in size to 91 square miles.