The name "Niagara" (Iroquois Nation pronunciation "Nee-ah-GAh-rah") is said to originate from an Iroquois word "Onguiaahra" meaning "The Strait." The region's original inhabitants were the Ongiara, an Iroquois tribe named the Neutrals by French settlers, who found them helpful in mediating disputes with other tribes.

A number of figures have some stake to the honor first circulating an eyewitness description of Niagara Falls. Frenchman Samuel de Champlain visited the area as early as 1604 during his exploration of Canada and members of his party reported to him the spectacular waterfalls, which he describe in his journals. Finnish-Swedish naturalist Pehr Kalm, explored the area in the early 1700s and wrote of the experience.

The consensus honoree is Belgian Father Louis Hennepin, who observed and described the Falls in 1677, earlier than Kalm, after traveling with explorer Rene' Robert Cavelier, Sieur de la Salle, thus bringing the Falls.

Further complicating matters, also there is credible evidence, that French Jesuit Reverend Paul Ragueneau visited the falls some 35 years prior to Hennepin's visit while working among the Huron First Nation in Canada. Jean de Brebeuf also may have visited the falls while spending time with the Neutral nation.

Source: Wikipedia