[3] Acting as a major gateway for US–Asian trade, the port occupies 3,200 acres (13 km2) of land with 25 miles (40 km) of waterfront in the city of Long Beach, California.

[5][6] The San Pedro Breakwater was started in 1899 and over time was expanded to protect the current site of the Port of Long Beach.

The Port of Long Beach was founded on 800 acres (3.2 km2) of mudflats on June 24, 1911, at the mouth of the Los Angeles River.

Due to the booming economy, Long Beach voters approved a $5 million bond to improve the inner and outer harbor in 1924.

[14] Engineers and geologists were promptly assigned to the problem, building dikes for flood control at high tide.

On July 3, 1930 the Federal River and Harbor Act authorizes expanding the San Pedro Bay breakwater by 3.5-mile completed in 1949.

The first bridge linking the eastern end of Terminal Island and Long Beach across the Back Channel was an unnamed "temporary" pontoon bridge constructed during World War II to accommodate traffic resulting from the expansion of the Long Beach Naval Shipyard.

Concerns regarding subsidence increased until Operation "Big Squirt," a water injection program, halted any progression of sinking land in 1960.

[20] In 1971 Pier J expansion is complete with a 55-acre container and car import terminal, becoming Toyota's Western distribution center.

The Port of Long Beach instituted programs to prevent and control oil spills, contain debris, and manage vessel traffic.

Relationships were forged with other international powers, and South Korea's Hanjin Shipping opened a 57-acre (230,000 m2) container terminal on Pier C of the port in 1991.

By using enclosed conveyors and covered storage areas, the port reduced the amount of dust emitted by the petroleum coke by 5%, down 21% in 1997.

[29] In 2012 International Longshore and Warehouse Union went on strike, that closed down the ports of and Long Beach and Los Angeles.

[30][31] In April 2019, COSCO Shipping-owned Orient Overseas (International) Limited announced that it would sell their Long Beach Container Terminal business to a consortium led by Macquarie Infrastructure Partners for $1.78 billion.

[32] The federal government demanded the sale of the terminal after a 2018 review by the Committee on Foreign Investment in the United States.

[36] A decision in 2020 by the California Public Utilities Commission allowed building a fuel cell plant at the port to move ahead.

A 400-acre terminal area (160 ha) would be built on new land composed of dredged material for assembling the tall structures.

On the state level, the Port of Long Beach provides about 370,000 jobs and generates close to $5.6 billion a year in state and local tax revenues[41] The port is served by the Alameda Corridor through which intermodal railroad cars go north to Los Angeles.

The policy sets a framework for enhancing wildlife habitat, improving air and water quality, cleaning soil and undersea sediments, and creating a sustainable port culture.

Established by the Long Beach Board of Harbor Commissioners, it is the largest voluntary effort of its kind in the nation.

The Green Flag incentive program was set up to encourage ships to slow down in order to improve air quality.

The Green Flag program provides approximately $2 million a year in discounts for vessel operators who slow their ships to 12 knots (22 km/h) or less within 20 miles (32 km) of the harbor.