Buck O’Neil Signed Postcard Kansas City Monarchs Negro League Baseball JSA AutoBuck ONeil signed Kansas City Monarchs postcard, authenticated by JSA Postcard was issued by the Negro Leagues Baseball Museum John Jordan "Buck" O'Neil Jr. was a first baseman and manager in the Negro American League, mostly with the Kansas City Monarchs. After his playing days, he worked as a scout and became the first African American coach in Major League Baseball JSA authentication #AI74382 3. 5" x 5. 5" Excellent condition; minimal cornerwear,