Here you see Prospect Point on Niagara Falls under illumination by floodlight in 1939. This was a new feature at the falls as the postcard relates on the back.
When the new floodlights are marching across the Falls, and resting on either or both of the American and Canadian faces of them or playing in the mist of spray above them they are described by beholders as more beautiful than ever the spray and the Sun combined could make the in the past, or than ever the Moon and the mist could make them. The effect is described as one suggesting that both the Sun and the Aurora Borealis have combined to do the utmost in the creation of a new spectacle.
It sounds like a sight to see to when you get out there on the road and tour the great, big, beautiful United States of America.