European explorers searched in vain for a northwest waterway through the North American continent. French traders living in the northeast heard of a great river that the natives called Messi-Sipi to the west. Was this river the Northwest Passage? Or was the Messi-Sipi really the Rio Grande, the river that Hernando de Soto had discovered a century earlier? That's what Father Jacques Marquette and his companion explorer Louis Jolliet hoped to discover in 1673. It's hard to imagine a more unlikely explorer and hero than Father Jacques Marquette, yet his gentle and compassionate nature made him the perfect ambassador to the friendly native peoples they met along the banks of the great Mississippi River.