in 1993 the bureau of indian affairs (bia) acknowledged that the brothertown indians had been recognized as a sovereign tribe by the federal government in provisos to treaties of 1831 and 1832, and in the 1839 act granting them citizenship and allocation of lands in wisconsin. the office of the solicitor of the department of interior confirmed in writing to the tribe that the brothertown indian nation was eligible to petition the bia for federal recognition, a process that the tribe has been pursuing. had congress's granting of citizenship status stripped the brothertown indian nation of its federal acknowledgment in 1839, the tribe would have been deemed ineligible for the bia's federal acknowledgment process (25 cfr sec. 83), and only an act of congress could give the tribe federal acknowledgment. based on the bia's ruling, the brothertown indians spent several years compiling the data required to petition for federal recognition from the department of interior's bia and submitted a detailed petition in 2005.