The thing about GULAG as an institution wad that it's existence depended on making criminals. Forced prison labor was part of the Stalinist primitive accumulation strategy, and that entailed as a matter of institutional design the arbitrary and capricious arrest of millions.
While obviously the UASR has no need for such methods, prison labor was already a major part of the US prison system, and that will continue after the Revolution, with greatly swelled ranks of reactionaries. While more extensive than OTL convict labor in America, inmates have more rights, including remuneration. And the system largely becomes obsolescent in WW2, as most of the prison population are granted reprieve, commutation or amnesty to free up labor for the war economy.