the Baylor University Chamber of Commerce. March 19 – United States Congress refuses to ratify the Treaty of Versailles. March 28 – The 1920 Palm Sunday tornado outbreak hits the Great Lakes region and Deep South states. April April 28 – Monongahela National Forest is established. May May 2 – The first game of the Negro National League baseball is played in Indianapolis, Indiana. June June 11 – During the 1920 Republican National Convention in Chicago, party leaders gather in a "smoke-filled room" of The Blackstone Hotel to decide their presidential candidate. June 13 – The U.S. Post Office rules that children may not be sent via parcel post. June 14 – Cherokee National Forest is established. June 15 – 1920 Duluth lynchings: Three African Americans are sprung from jail and lynched by a white mob in Duluth, Minnesota. June 21 – The 4.9 Inglewood earthquake shakes the Los Angeles Area with a maximum Mercalli intensity of VIII (Severe), causing more than $100,000 in damage. July July 1 – The Oahu sugar strike of 1920 ends. July 6 – Lynching of Irving and Herman Arthur in Paris, Texas. July 29 – The United States Bureau of Reclamation begins construction of the Link River Dam as part of the Klamath Reclamation Project. August August 1–6 – Denver streetcar strike of 1920 August 20 The first commercial radio station in the U.S., 8MK (WWJ), owned by the Detroit News, begins operations in Detroit, Michigan. The National Football League is founded as the American Professional Football Conference (renamed September 17 as 'Association'). August 26 – Nineteenth Amendment to the United States Constitution is passed, guaranteeing women's suffrage. September September 16 – The Wall Street bombing: a bomb in a horse wagon explodes in front of the J. P. Morgan Building in New York City – 38 dead, 400 injured. September 29 – First domestic radio sets come to stores in the U.S. – Westinghouse radio costs $10. October–November November 2 Republican U. S. Senator Warren G. Harding defeats Democratic Governor of Ohio James M. Cox in the U.S. presidential election, the first national U.S. election in which women have the right to vote. KDKA (AM) of Pittsburgh, Pennsylvania (owned by Westinghouse) starts broadcasting as a commercial radio station. The first broadcast is the results of the presidential election. November 2–3 – Ocoee massacre occurs. December December 25 – Foundation of the Rosicrucian Fellowship's