Final answer:
The fraud perpetrated on the Indians in Pennsylvania is known as the Walking Purchase, which involved William Penn's sons and other colonists defrauding the Lenape Indians out of more land than they had originally agreed to after Penn's death.
Step-by-step explanation:
The fraud perpetrated on the Indians in Pennsylvania is known as the Walking Purchase. After the death of William Penn, his sons, along with other colonists, tricked the Lenape Indians into ceding more land than they had agreed to. This notorious event involved a deceitful interpretation of a previous verbal agreement where the amount of land to be sold was to be covered by a man walking in a day and a half. Instead of a normal walk, Penn's sons hired a team of runners who marked out an area much larger than what the Lenape had intended to sell. This led to the displacement of indigenous tribes and disrupted the peace and friendly relations William Penn had established with the Native Americans, eventually contributing to the tribes' alignment with the French.
It's important to note that the fair and kind treatment of the Indians was initially a cornerstone of the colony's success. However, with the expansion needs of European settlers and ambiguous treaty terms, the respect for Native American land rights sadly diminished over time.