Can you acknowledge that Native Americans and the state and federal US gov'ts made agreements? in some cases giving them some sovereignty and land?
Yes, that's established history. However, there are many agreements that have come into being in history and are no longer valid.
Those agreements were signed when Native American nations were operating as functioning nation-states. Since 1924, every Native American has been a U.S. citizen, there is no more Native American citizenship only tribal membership that can be freely given or revoked (and frequently is), and the persons claiming tribal membership today have almost no genetic relation to those who signed the agreements (and, in fact, they are more genetically related to the representatives of the U.S. and state governments that oppressed the actual Native Americans, before that culture went extinct).
A nation-state can't exist without any citizens. Membership is not a synonym for citizenship, otherwise the AAA would be a sovereign nation. The nation-states no longer exist. There are only shells, a legal fiction built on a cultural fiction that is funded by Caesar's and Harrah's as a complex tax shelter; an ingenious scheme by which multi-billionaire dollar corporations can avoid paying taxes without generating the mildest squeak of protest from progressives.
in some cases giving them some sovereignty and land?
They have never had sovereignty as the term is understood in law. "Sovereignty" is a word of art used by the so-called "Native Americans" (the 1% of the white population claiming to be connected to the extinct culture of aboriginal Americans).
Since 1831 they have been internal dependencies of the United States like the Isle of Mann is to the UK. They are,
at most, autonomous. They are not sovereign. They do not have any of the elements of sovereignty: they do not engage in diplomatic relations with other sovereign states, they do not have a monopoly on political violence in their territory (federal law enforcement has an absolute right to enter tribal territory even if state police do not), and they do not enjoy any of the rights accorded to sovereign states under international law such as control of airspace or maritime EEZs. Indeed, with the exception of the Navajo and the Eastern Band of the Cherokee, none of them even have a significant enough population to viably operate as a sovereign state.