when can we say that workers are alienated from their work from their fellow workers
Marx's theory of alienation Capitalism reduces the labour of the worker to a commercial commodity that can be traded in the competitive labour-market, rather than as a constructive socio-economic activity that is part of the collective common effort performed for personal survival and the betterment of society. In a capitalist economy, the businesses who own the means of production establish a competitive labour-market meant to extract from the worker as much labour (value) as possible in the form of capital. The capitalist economy's arrangement of the relations of production provokes social conflict by pitting worker against worker in a competition for "higher wages", thereby alienating them from their mutual economic interests; the effect is a false consciousness, which is a form of ideological control exercised by the capitalist bourgeoisie through its cultural hegemony. Furthermore, in the capitalist mode of production the philosophic collusion of religion in justifying the relations of production facilitates the realization and then worsens the alienation (Entfremdung) of the worker from their humanity; it is a socio-economic role independent of religion being "the opiate of the masses".[3]
Gilded Age In terms of immigration, after 1880 the old immigration of Germans, British, Irish, and Scandinavians slackened off. The United States was producing large numbers of new unskilled jobs every year, and to fill them came number from Italy, Poland, Austria, Hungary, Russia, Greece, and other points in southern and central Europe, as well as French Canada. The older immigrants by the 1870s had formed highly stable communities, especially the German Americans.[102] The British immigrants tended to blend into the general population.[103]