"All who recall the condition of the country in 1890 will remember that...the country was in real danger from another kind of slavery...that would result from the aggregations of capital in the hands of a few individuals and [businesses] controlling, for their own profit and advantage exclusively, the entire business of the country, including the production and sale of the necessaries of life." -Supreme Court Justice John Marshall Harlan, 1911

In this excerpt, Justice Harlan is warning against-

a civil service based on patronage rather than merit

allowing labor unions to interfere with production goals

allowing powerful monopolies to dominate interstate commerce

a lack of federal funding for essential transportation systems

allowing powerful monopolies to dominate interstate commerce

Explanation:

In late 1800s, United States faced massive problem in its economy. At the time, many corporations conducted unethical businesses practices that make them become the sole producer of a certain product and working together in a price-fixing scheme.

This make the common people have to pay their products with a significantly higher price while having to survive with low wages & terrible standard of living. The government managed to put an end to this practice by passing the Sherman Antitrust Act  on July 2 1890.

In his speech above, John Marshall Harlan was warning the people about this. He didn't want them to forget what happened if the country let  powerful monopolies to dominate interstate commerce.

its main object was the establishment of "settlement houses" in poor urban areas, in which volunteer middle-class "settlement workers" would live, hoping to share knowledge and culture with, and alleviate the poverty of, their low-income neighbors.