It was 'The Great Migration.'
"The Great Migration<span> was the movement of 6 million African-Americans out of the rural Southern United States to the urban Northeast, Midwest, and West that occurred between 1910 and 1970."</span>
Tenement dwellers face hardships, or deprivation. Tenement dwellers are people who dwell on old or crowded house or apartment. Tenement dwellers are mostly found in the deprived area of a city, or where less-privileged persons commonly stay. Tenement dwellers mostly stay in abandoned houses, apartments.
Analyzing and breaking coded messages
electronic surveillance
analyzing data from spy satellites
But I mean your security so it could be multiple things
Offered advice on getting and keeping power