Read the passage. Morgan originated, and made large profits from, numerous other mergers. Acting as primary banker to numerous railroads, moreover, he effectively muted competition among them. His organizational efforts brought stability to American industry by ending price wars to the disadvantage of farmers and small manufacturers, who saw him as an oppressor. In 1901, when he established the Northern Securities Company to control a group of major railroads, President Theodore Roosevelt authorized a successful Sherman Antitrust Act suit to break up the merger.

–"J. P. Morgan and Finance Capitalism,”
Outline of U. S. History,
Alonzo Hamby

One result of decreased competition within a market is notably increased

access to innovative goods and lower long-term prices for consumers.
tax revenue for state and local governments.
fraud and corruption among business leaders and elected officials.
ability for the remaining large firms to compete in foreign markets.