Remembering immigrant opposition to Emancipation on Juneteenth holiday:  For eight days in July 1834, immigrants fear of the mere possibility of a future flood of newly freed slaves from the South competing with them for jobs in New York City boiled over into a fullscale riot involving thousands.                 The new Junnteenth holiday coming up on June 19 is a time not only to celebrate the federal ending of slavery after the Civil War but also to think about the forces that had long opposed Emancipation.  The 1834 Labor Riots of New York was the prime example of the fact that the freeing of the American Slaves was resisted not only in the South but also in the North, most vigorously by new immigrants from Europe.     A bigger culprit than the immigrants were elected officials who ran mass immigration policies without any thought to whether they were creating powder kegs of labor desperation and fear that could fuel resentment and violence between races.                 The immigrant labor riots of 1834 and all the other anti-emancipation riots across the North would be largely forgotten by 21st century Americans in part because of the exceptionally more violent and vicious immigrant labor riots of 1863.           The labor tensions could have been reduced if the government had curtailed the continuous arrival of ships full of new foreign workers whose volume was further undercutting employment opportunities for earlier immigrants and inflaming their passions.  Instead, the government allowed the volume of new and unneaded foreign workers to rapidly increase and even encourage it.  All the way to 370,000 in 1850. More immigrants arrived in the three years of 1848 through 1850 than arrived the entire decades of the 1820s and 1830s combined.                                             Organizing themselves into trade Unions was one way the immigrants were able to tighten the labor market for those fortunate enough to be allowed into the unions. Immigrant laborers were able to set the terms of hiring at many urban workplaces. Not only did they bar Black workers from their Unions, but they usually refused to work alongside them if employers hired African Americans. Because of that refusal on the part of the more numerous immigrant workers, many firms decided not to hire Black workers at all, or to fire the ones already on the site.     "Back of the Hiring Line":  A 200-year history of immigration surges, employer bias, and depression of Black wealth - ROY BECK - Founder of NUMBERSUSA