Christina Duffy Burnett says that the document, titled The Sovereignty of Islands Claimed Under the Guano Act and of the Northwest Hawaiian Islands, Midway, and Wake, argued that the discovery that bird guano found on islands is a very effective fertilizer lead to the U.S. Government asserting claims over many islands:
"The stuff is like magic, and farmers everywhere are suddenly clamoring to get their hands on some. There's a boom, the price skyrockets, the Peruvians more or less control the market, and supplies are short. Everybody is looking for new sources, there's tons of fake guano trading hands-it's chaos. Enter the US farm lobby. Farmers in the United States start pressuring Congress to pass some sort of legislation that will improve domestic access to this vital excrement. The result is the Guano Islands Act, legislation that authorized the United States to take control of a guano island if a citizen discovered it and undertook certain actions to take possession of it."