After the Great Depression, World War II, and U.S. federal income taxes made it more difficult to staff and operate stately homes like "The Farms", the Allertons moved to Lawai-Kai (now Allerton Garden), Kaua'i, Hawaii, in 1946, after deeding the Piatt County property to the University of Illinois. At the time, taxes on Allerton land accounted for one-fifth of all tax revenue to support public works in the Willow Branch Township. The university, however, disputed its obligation to pay taxes on the estate, citing itself as a non-profit, tax exempt state institution. The Township, not wishing to lose a significant portion of its tax funding, protested. The University was found in 1949 to be in delinquency of unpaid real estate taxes. A later Illinois Supreme Court ruling resolved the matter: the University would make an annual payment in lieu of taxes to Piatt County. The public park and woodland acreage are today tax-exempt; only the income-generating farmland is taxed.