Answer by taking a quote from the following article:

Lemon Henry "Blind Lemon" Jefferson (September 24, 1893 - December 19, 1929) was an American blues and gospel singer, songwriter, and musician. He was one of the most popular blues singers of the 1920s and has been called the "Father of the Texas Blues". Jefferson's performances were distinctive because of his high-pitched voice and the originality of his guitar playing. His recordings sold well, but he was not a strong influence on younger blues singers of his generation, who could not imitate him as easily as they could other commercially successful artists.

Jefferson was born blind (or possibly partially blind), near Coutchman, Texas. He was the youngest of seven (or possibly eight) children born to Alex and Clarissa Jefferson, who were sharecroppers. Disputes regarding the date of his birth derive from contradictory census records and draft registration records. By 1900, the family was farming southeast of Streetman, Texas, and his birth date is indicated as September 1893 in the 1900 census. The 1910 census, taken in May, before his birthday, further confirms his year of birth as 1893 and indicated that the family was farming northwest of Wortham, near his birthplace.  In his 1917 draft registration, Jefferson gave his birth date as October 26, 1894, further stating that he then lived in Dallas, Texas, and had been blind since birth. In the 1920 census, he is recorded as having returned to Freestone County and was living with his half-brother, Kit Banks, on a farm between Wortham and Streetman.  Jefferson began playing the guitar in his early teens and soon after he began performing at picnics and parties. He became a street musician, playing in East Texas towns in front of barbershops and on street corners. According to his cousin Alec Jefferson, quoted in the notes for Blind Lemon Jefferson, Classic Sides:  They were rough. Men were hustling women and selling bootleg and Lemon was singing for them all night... he'd start singing about eight and go on until four in the morning... mostly it would be just him sitting there and playing and singing all night.  In the early 1910s, Jefferson began traveling frequently to Dallas, where he met and played with the blues musician Lead Belly. Jefferson was one of the earliest and most prominent figures in the blues movement developing in the Deep Ellum section of Dallas. It is likely that he moved to Deep Ellum on a more permanent basis by 1917, where he met Aaron Thibeaux Walker, also known as T-Bone Walker. Jefferson taught Walker the basics of playing blues guitar in exchange for Walker's occasional services as a guide. By the early 1920s, Jefferson was earning enough money for his musical performances to support a wife and, possibly, a child. However, firm evidence of his marriage and children has not been found.

Who are his parents?
Alex and Clarissa Jefferson, who were sharecroppers.