After St. Peter's death Constantine had the Basilica built. He later dedicated it to Peter. The baldacchino was created by Lorenzo Bernini from 1624 to 1633. The excavations below the church include Pope John Paul II and St. Peter's remains as I mentioned in one of my paragraphs. Its important for people to know and understand the history behind the basilica. 

Images: 

http://www.sacred-destinations.com/italy/rome-st-peters-basilica-photos/