Answer by taking a quote from the following article:

William Patrick Corgan Jr. (born March 17, 1967) is an American musician, songwriter, producer, poet, and professional wrestling magnate. He is best known as the lead singer, primary songwriter, guitarist, and sole permanent member of The Smashing Pumpkins. Formed by Corgan and guitarist James Iha in Chicago, Illinois, in 1988, the band quickly gained steam with the addition of bassist D'arcy Wretzky and drummer Jimmy Chamberlin. Strong album sales and large-scale tours propelled the band's increasing fame in the 1990s until their break-up in 2000.

William Patrick Corgan Jr. was born at Columbus Hospital in Chicago's Lincoln Park neighborhood on March 17, 1967 as the oldest son of William Corgan Sr., a blues/rock guitarist, and Martha Louise Maes Corgan Lutz. He was raised Catholic. His parents had one more son, Ricky, before divorcing in 1970. His father was soon remarried to a flight attendant, and Corgan and his brother went to live with them in Glendale Heights, Illinois. During this time, Corgan alleges he was subject to much physical and emotional abuse by his stepmother. Corgan also developed a protective bond with his younger paternal half-brother, who had special needs as a child. When Corgan's father and stepmother separated, all three boys would live alone with the stepmother, with both of Corgan's birth parents living separately within an hour's drive.  Corgan, who grew much faster than his fellow students, was a strong athlete in elementary school. In addition to being a member of his Marquardt Middle School baseball team, he collected baseball cards (amassing over 10,000) and listened to every Chicago Cubs game. However, by the time he began attending Glenbard North High School in Carol Stream, Illinois, he had become only an average athlete. He decided to start playing guitar when he went over to a friend's house and saw his friend's Flying V. Corgan gave his savings to his father, who bought him a used Les Paul knock-off. Corgan, Sr. steered his son stylistically, encouraging him to listen to Jeff Beck and Jimi Hendrix, but offered little other support, and the younger Corgan taught himself to play the instrument. His musical interests in his formative years included hard rock like Guts-era John Cale, heavy metal pioneers Black Sabbath, and mainstream rock like Queen, Boston, ELO, Rush, and Cheap Trick. In high school, Corgan discovered alternative rock through Bauhaus and The Cure.  Corgan performed in a string of bands in high school, and graduated as an honor student. Despite grant and scholarship offers from a number of schools, and a tuition fund left by his grandmother, Corgan decided to pursue music full-time. Not finding the Chicago music scene to his liking, he moved from Chicago to St. Petersburg, Florida in 1985 with his first major band, The Marked (so named for the conspicuous birthmarks of both Corgan and drummer Ron Roesing). Not finding success in St. Petersburg, the band dissolved; Corgan moved back to Chicago to live with his father.  Corgan performed with Wayne Static in Static's first band Deep Blue Dream, in 1987/88.

Was that the first band he was part of?
Corgan performed in a string of bands in high school,