1901: Alexander Winton, widely considered the first manufacturer of passenger cars for the general market, introduces his two-cylinder automobile engine.
1903: Alwin and Theodore Ernst open an accounting office in downtown Cleveland, beginning the firm that would later become the worldwide accounting firm of Ernst & Young LLP.
1904: Cleveland Cap Screw Co., a forerunner of TRW Inc., produces a new type of automobile valve that greatly enhances the durability of engines, the first of many technological innovations.
1918: Aviation designer Glenn Martin produces Clevelands first airplane, the MB-2 bomber. He later relocates to Baltimore. Despite several mergers in the decades since, his name still lives on in Lockheed Martin, the nations biggest defense contractor.
1921: George Crile and three other doctors establish the Cleveland Clinic Foundation.
1927: The 52-story Terminal Tower opens, reigning for decades as the tallest building between New York and Chicago.
1928: Louis Seltzer appointed editor of the Cleveland Press. For the next 38 years, he is arguably the most powerful man in Cleveland, controlling what is perhaps its most influential institution. The paper closed in 1982.
1929: Cyrus Eaton consolidates his steel holdings into Republic Steel Corp., the countrys third-largest steel company. He would soon lose most of his $100-million fortune in the Depression.
1936: A sit-down strike at a General Motors Fisher Body plant on Coit Road serves as a catalyst for the mass unionization of auto workers nationally.
1937: More than 40 years after he left Cleveland, the body of John D. Rockefeller is returned for burial in Lakeview Cemetery.
1947: A forerunner of NASA establishes the Lewis Research Center near Hopkins Airport. It would later become a significant producer of spin-off research for industry.
1947: A merger of Mather familys iron ore interests creates the second largest ore holdings in the country, after U.S. Steel.
1949: Cleveland drafts a comprehensive general plan (replacing the elegant Group Plan of 1903) to guide downtown development, representing, as one historian later observed, the triumph of the City Efficient over the City Beautiful. It was still being used as the blueprint until well into the 1980s.
1959: St. Lawrence Seaway opens, providing a direct water link between Cleveland and the Atlantic Ocean, and sparking considerable investment in port facilities. Predictions of booming international trade to and from the city prove considerably inflated.
1969: Cuyahoga River catches fire, resulting in nationwide ridicule, but touching off sustained efforts to clean up the river and the body of water into which it flows, Lake Erie.
1967: The Cleveland Chamber of Commerce and the Greater Cleveland Growth Board merge, prompting the successor, the Greater Cleveland Growth Association, to label itself the largest local chamber of commerce in the country.
1972: Community activist Ray Shepardson organizes protests the razing of three vintage Euclid Avenue theatres: the State, the Ohio and the Allen. The corporate community later provides seed funding to restore what is eventually named Playhouse Square. While the Rock and Roll Hall of Fame and Gateway grab headlines some 20 years later, this is the beginning of Clevelands downtown turnaround.
1973: The NAACP files a federal lawsuit claiming discrimination in Clevelands public schools, leading to the 1976 busing order by Judge Frank Battistimarking steep decline in a once-respected urban school district.
1978: The City of Cleveland defaults on its long-term debt, the first major American city to do so since the Great Depression.
1986: To the chagrin of mysterious powers in New York City, Cleveland is selected as the site for the Rock and Roll Hall of Fame. I.M. Peis impressive, if impractical, structure opens nine years later.
1995: The resurgent Cleveland Indians win the American League pennant for the first time in 41 years.