Machu Picchu grown rapidly. In 1912, 1914 and 1915, Bingham removed thousands of artifacts from Machu Picchu—ceramic vessels, silver statues, jewelry and human bones—and took them to Yale University for further study, supposedly for 18 months. Yale instead kept the artifacts until 2012, arguing that Peru lacked the infrastructure and systems to care for them. Eliane Karp, an anthropologist and wife of former Peruvian President Alejandro Toledo, accused Yale of profiting from Peru's cultural heritage. Many of the articles were exhibited at Yale's Peabody Museum. In 2006, Yale returned some pieces but kept the rest, claiming this was supported by federal case
Machu Picchu the accusations, claiming that the excavation harmed the site and deprived local archaeologists of knowledge about their own history. Landowners began to demand rent from the excavators. By the time Bingham and his team left Machu Picchu, locals had formed coalitions to defend their ownership of Machu Picchu and its cultural remains, while Bingham claimed the artifacts ought to be studied by experts in American institutions. Little information describes human sacrifices at Machu Picchu, though many sacrifices were never given a proper burial, and their skeletal remains succumbed to the elements. However, there is evidence that retainers were sacrificed to