HARTFORD, Conn. — The U.S. Interior Department on Thursday announced proposed changes to the rules for granting federal recognition to American Indian tribes, revisions that could make it easier for some groups to achieve status that brings increased benefits as well as opportunities for commercial development. The Bureau of Indian Affairs says it overhauled the rules to make tribal acknowledgment more transparent and efficient. The changes include a new requirement that tribes demonstrate political authority since 1934, where they previously had to show continuity from “historical times.” That change was first proposed in a draft last June and stirred criticism that the standards for recognition were being watered down. Kevin Washburn, an assistant secretary with Indian Affairs, said the rules are no less rigorous. He said 1934 was chosen as a dividing line because that was the year Congress accepted the existence of tribes as political entities.Gerald Gray, chairman of Montana’s Little Shell Tribe of Chippewa Indians, said the changes offer the path to recognition that his people have sought for decades. The landless tribe of about 4,500 members has been recognized by the state of Montana since 2000, but its bid for federal recognition was rejected in 2009 partly because the tribe could not document continuity through the early part of the 20th century. Gray said that denial illustrated how the process is broken.