Toned and clear coated Ken-Wel "American League" baseball which has been autographed by approximately several players with relation to Cuban baseball. Most significantly is the apparent presence of Jose de la Caridad Mendez. Nicknamed "El Diamante Negro" (The Black Diamond), Mendez is regarded as one of the most prominent figures in the history of Cuban baseball. Mendez pitched in the Negro Leagues during the early part of the 20th century and dominated his opponents with a deceptive fastball and penchant to switch pitch speeds at will. Mendez routinely played in various exhibition games besting his MLB counterparts including Christy Mathewson and Eddie Plank. Philadelphia Athletics catcher Ira Thomas remarked after the Athletics travelled to Cuba to face Mendez, "More than one big leaguer from the states has faced him and left the plate with a wholesome respect for the great Cuban star. It is not alone my opinion but the opinion of many others who have seen Méndez pitch that he ranks with the best in the game.” After his playing career Mendez briefly went on to manage as well before tragically contracting tuberculosis and passing away in 1928 at the age of 41. Mendez was one of the first Cuban players to be elected to the Cuban Baseball Hall of Fame in 1939 and in 2006 was selected for enshrinement to the National Baseball Hall of Fame. Given Mendez untimely passing at such a young age and the lack of accessibility during his career due to geography and Cuban heritage, memorabilia artifacts with relation to Mendez are virtually non-existent. The offered baseball originated from the personal collection of Manuel Ogea who was a Cuban watchmaker and avid collector of baseball items of historical interest. The ball was acquired by a collector from Ogea in 1990 and subsequently offered for sale only once until it current presentation. Side panel of the ball displays a period ink signature, "Jose de la Caridad Mendez". The signature remains clearly legible rating 7 out of 10. Additional signatures on the baseball include A.Cabrera (prominent Cuban player who broke into MLB in 1913 with the St. Louis Cardinals), R.Atan (played for Almendares in 1920s), and A.Suarez (aka Mike Gonzales) as US players were often prohibited from playing in Cuba and assumed aliases. Signatures of the other players range between 3-5 out of 10. Notably, both Mendez and Cabrera played for the Almendares between 1913-16 thus providing contextual reasoning for their presence on the ball. Additional ink inscription is found on a side panel in Spanish which translates, "Remembrance of a game....Almendares, June ?? , 1928." Jose Mendez's autograph is quite literally a collecting impossibility. To the best of our knowledge, this is the only specimen of any credibility, on any medium, known to exist. The scarcity of course makes formal authentication a formidable challenge with no documented exemplars to assist with same. Neither JSA or PSA were able to formally authenticate the baseball for not other reason than lack of exemplars as mentioned. JSA was able to provide a letter of opinion that "does not prohibiting the ball from being signed by Jose Mendez." The letter includes scans of the signature under the Video Spectral Comparator which clearly shows the Mendez signature in addition to the "Almendares" reference. Additional points of supportive corroboration are also included within the JSA letter noting the manufacturing era of the ball itself and confirmation of ink consistency to the stated time period. Based on the aforementioned we feel confident in a strong attribution to the baseball having been signed by The Black Diamond himself, Jose Mendez. Mendez by all measures is the rarest 20th century Hall of Fame player autograph to acquire which would be the crown jewel of any advanced collection. Includes letter of opinion from JSA and a copy of the original letter of provenance related to Manuel Ogea: Ball: VG, Mendez signature: EX, Additional signatures: Range PR-VG/EX