Between 1900 and the mid 1950s, Cleveland laid claim to being one of the largest cities in America, ranking between 5th and 7th place for five decades.1 Its population grew in pace with its industrial complex, and its downtown skyline took shape while landscapers and naturalists readied its unprecedented network of public parks.
"They call her the Sixth City, but that is only in a comparative sense, and exclusively in regard to her statistical position in the population ranks of the large cities of our land. For no real citizen of Cleveland will ever admit that his community is less than first, in all of the things that make for the advance of a strong and healthy American town. His might better be called "the City of Boundless Enthusiasm." Your Cleveland man, however, is content to know it as the Sixth City.
"And Cleveland having thus baptized herself, as it were, proceeded to spread her new name to the world. 'Cleveland — Sixth City' appeared on the stationery of her business houses; her tailors stitched it in upon the labels of the ready-made suits they sent to all corners of the land; her bakers stamped it on the products of their ovens; big shippers stenciled it over packing-cases; manufacturers even placed it upon the brass-plates of the lathes and other complicated machines they sent forth from their shops. Today when you say 'Sixth City' to an American he replies, 'Cleveland,' which is precisely what Cleveland intended he should reply."2
The Ingalls Library has a small but impressive collection of postcards from the Cleveland Sixth City era. Acquired predominantly in the 1940s and 1950s, the collection features: Public Square and prominent public buildings downtown, Wade Park and Gordon Park, the lakefront, with its busy port, the city's high schools and colleges, elegant bridges, banks, and churches, and the scenic ride to nearby Rocky River.
A panoramic postcard of Cleveland's Public Square (at top of page) shows yellow streetcars on Superior Avenue, and calls attention to the 'New Post Office' – that is, the Post Office & U.S. Custom House, opened in 1910 as the first of the Cleveland Group Plan of Public Buildings.3
Cleveland's Union Terminal Tower, on Public Square's southwest corner, was dedicated in 1930 after almost a decade of planning and construction. The downtown terminal served all rail lines, except the Pennsylvania Railroad, through 1973.4
Cleveland's bustling lake front is shown on a panoramic postcard, sent by "Chas German" to "My Dear Friend, Miss George" in 1908. Passenger liners and freight cars crowd the lakefront rail lines; the Cleveland Central Armory is visible in the emerging Cleveland skyline.
The Cleveland Sixth City logo is featured on a postcard of the elegant, arched Rocky River Bridge, which connected the wealthy suburbs of Rocky River and Lakewood. At the time of its dedication in 1910, the bridge was the largest concrete arch in the world.
One pair of postcards, hand-canceled in late Summer 1909, reflects correspondence between a "Miss Curtis, Marietta, Ohio," and "A.B.C." The fronts of the postcards depict Mr. Cleveland and Miss Columbus, the lions featured in the Wade Park Zoo. The zoo moved in phases to the current Brookside Park site of the Cleveland Metroparks Zoo between 1907 and 1914, to make way for the construction of the Cleveland Museum of Art.5
The Ingalls Library's postcards of Cleveland preserve the spirit and excitement of the Cleveland Sixth City era and illustrate the history of one of 20th century America's most progressive cities.
For more additional images of Cleveland via postcard, visit Postcards of Cleveland: 8000 postcards from the collection of Dr. Walter Leedy, at http://www.clevelandmemory.org/postcards/ 
1. United States Census Bureau. "Census 2000 PHC-T-5. Ranking Tables for Incorporated Places of 100,000 or More: 1990 and 2000". United States Census, 2000. http://www.census.gov/population/cen2000/phc-t5/tab02.txt  Retrieved 11 Jan. 2010.
2. "Cleveland The Sixth City". Antiques Digest. http://www.oldandsold.com/articles33n/american-cities-12.shtml  Retrieved 11 Jan. 2010.
3. "Cleveland: A Bicentennial Timeline". The Encyclopedia of Cleveland History, Case Western Reserve University. http://ech.case.edu/timeline.html  Retrieved 11 Jan. 2010.
4. Rose, William Ganson. (1950). Cleveland: The Making of a City [reprint]. Kent, Oh.: Kent State University Press.
5. "Cleveland: A Bicentennial Timeline". The Encyclopedia of Cleveland History, Case Western Reserve University. http://ech.case.edu/timeline.html  Retrieved 11 Jan. 2010.