What was the reason for liberty bonds poster world war i

A Liberty bond (or liberty loan) was a war bond that was sold in the United States to support the allied cause in World War I. Subscribing to the bonds became a symbol of patriotic duty in the United States and introduced the idea of financial securities to many citizens for the first time.

These islands/chinampas then provided rich soil for crops with easy access to water. i hope this is correct, im so sorry if its not !