The nineteenth-century movement that defended workers against their employers and questioned private property rights was

The labor movement of the 19th century was one that focused on defending workers against their employers. In America, many citizens faced awful working conditions that included an extreme amount of hours worked weekly (60+), small wages, unsafe working conditions, and no vacation time. These workers helped to form unions all across the United States.

Some of the most famous unions include:
1) American Federation of Labor
2) Knights of Labor
3) Federation of Organized Trades and Labor Unions.

These unions helped individuals get better pay, working conditions, and benefits from their employers.

The answer is installation.