For Native American tribes, treaties with the United States government have often led to displacement, removal and outright erasure.

But now, the Cherokee Nation is turning to treaties signed in the 18th and 19th centuries to push for a delegate to Congress for the first time in history. The treaties, the Nation claims, promised them a seat at the table.

“These treaties are sacred. They mean something. There’s no expiration date on them,” said Chuck Hoskin Jr., chief of the Cherokee Nation, who last week announced he would fulfill a longstanding legal right to appoint a delegate to Congress. “What I’m asking is for the government of the United States to keep its word.”

Charles Gourd, 70, the director of the Cherokee National Historical Society, said he and others had wondered with incredulity why no Cherokee Nation delegate had ever been seated in Congress despite assurances to that effect. Mr. Hoskin’s renewed push, weeks after he was sworn in as the new chief, in part reflects how far the Cherokee have come in terms of governance, Mr. Gourd said.