It was the least heralded migration in American history.Curious as to accuracy (100,000 applicants versus how many who actually emigrated?), I dug a little. From In Russia, Early American Migrants Found the Good Life by Ann M. Simmons, it appears that perhaps 18,000 workers emigrated to the Soviet Union.
At the height of the Depression, several thousand American emigrants left New York on the decks of passenger liners waving goodbye to the Statue of Liberty, bound for Leningrad.
Over 100,000 Americans had applied for jobs working in brand new factories in Soviet Russia, ironically built for Stalin by famous American industrialists such as Henry Ford.
Those American emigrants who entered the "workers' paradise" were certain that they were leaving the misery of unemployment and poverty behind them. They considered themselves fortunate.
Their optimism would prove to be short-lived. Most were stripped of their American passports soon after their arrival.
Considered suspect by Stalin's paranoid totalitarian state, the foreigners were swept away in the Terror.
The American jazz clubs, the baseball teams, and the English-language schools set up in cities across the USSR, would quickly vanish with them.
At the height of the Terror, the American emigrants had besieged their embassy, begging for passports so they could leave Russia.
They were turned away only to be arrested on the pavement outside by lurking NKVD agents.
Inside, the American diplomats had known about these disappearances almost from the very beginning. But they did little to save their fellow countrymen, whom they had christened "the captured Americans."
The emigrants began their long journey either into the prison cells and the Gulag camps, or the shorter route to the execution grounds.
In the killing fields at Butovo, a suburb 27 kilometres south-east of Moscow, several of the American baseball players were executed during the Terror, and lie buried in mass graves stretching for hundreds of metres.
Thousands were killed in this quiet country backwater, surrounded by trees to muffle their screams.
In its stillness lies the unimaginable horror of the Revolution that has spun out of control.
More detail here, In the Footsteps of a Forgotten Emigration - America, Russia and the Archaeology of Genocide by Tim Tzouliadis.