On this day in labor history, the year was 1912. That was the day the Anaconda Copper Company instituted its rustling card system at its copper mines in Butte, Montana. The company used the rustling card in two ways: as a work permit and as way to keep track of miners. A miner looking for work would first have to apply for a card. Miners had to present information about citizenship status, English literacy skills, work history and two years of employer references. Once the card was approved, the miner would then be allowed to apply for work. The Butte Miners’ Union charged it was the company’s way of blacklisting those who had quit, been fired or known as a union militant. By 1917, the Metal Mine Workers Union and the IWW added that the company was looking to “nip agitation in the bud.” They alleged employers were holding on to cards or denying them altogether for no reason. According to historian Paul Brissenden, both unions maintained the company was looking “to punish those who were at one time active in the socialist administration of Butte Mayor Lewis J. Duncan, to prevent the Socialist Party from again securing a foothold in Butte, to strengthen the hands of the more conservative unions and to curb the industrial unionism of the IWW and Metal Mine Workers Union.” The company asserted its right to keep its enemies out of the mines, alleging they presented a danger to mine safety. But the unions shot back, stating the blacklist meant the hiring of untrained, inexperienced workers who presented the real danger. Brissenden notes that many union radicals continued to work in the mines despite the card system.