As the system's scope grew to include quarantine authority and research, it was renamed the Public Health Service in 1912.

A series of reorganizations in 1966–1973 began a shift where PHS' divisions were promoted into departmental operating agencies.

[5] Modern public health began developing in the 19th century, as a response to advances in science that led to the understanding of the source and spread of disease.

Once it became understood that these strategies would require community-wide participation, disease control began being viewed as a public responsibility.

[7] In the administration of the second president of the United States John Adams, Congress authorized the creation of hospitals for mariners through the 1798 Act for the Relief of Sick and Disabled Seamen.

[11] He moved quickly to reform the system and adopted a military model for his medical staff; putting his physicians in uniforms, and instituting examinations for applicants.

Woodworth created a cadre of mobile, career service physicians, who could be assigned as needed to the various Marine Hospitals.

The commissioned officer corps was formally established by legislation after the fact in 1889, and signed by President Grover Cleveland.

[citation needed] The scope of activities of the Marine Hospital Service began to expand well beyond the care of merchant seamen in the closing decades of the nineteenth century, into control of infectious disease, collection of health statistics, and basic science research.

In 1912, under new authorizing legislation, it was established as the Public Health Service (PHS) to express the enlarged scope of its work.

[17] In 1913, the former Cincinnati Marine Hospital building was reopened as a Field Investigation Station for water pollution research.

[17][18][19] In 1914, the Office of Industrial Hygiene and Sanitation, the direct predecessor of the National Institute for Occupational Safety and Health, was founded at the Pittsburgh Marine Hospital.

[14] In 1930, the Hygienic Laboratory was redesignated as the (singular) National Institute of Health (NIH) by the Ransdell Act; in 1937, it absorbed the rest of the Division of Scientific Research, of which it was formerly part, and in 1938 it moved to its current campus in Bethesda, Maryland.

[25] PHS's headquarters were in the Butler Building, a converted mansion across the street from the United States Capitol, from 1891 until April 1929.

[22] The environmental health programs expanded from water pollution into air, industrial, and chemical pollution and radiological health research during and after World War II,[26][29] and in 1954 they moved across town from the former Cincinnati Marine Hospital to the newly constructed Robert A. Taft Sanitary Engineering Center.

[33] In 1953 the Federal Security Agency was abolished and most of its functions, including the PHS, were transferred to the newly formed Department of Health, Education and Welfare.

[37] The goal of the reorganizations was to coordinate the previously fragmented divisions to provide a holistic approach to large, overarching problems.

established many programs to help the poor in New York City keep their infants healthy, leading teams of nurses into the crowded neighborhoods of Hell's Kitchen and teaching mothers how to dress, feed, and bathe their babies.

Another key pioneer of public health in the U.S. was Lillian Wald, who founded the Henry Street Settlement house in New York.

The Visiting Nurse Service of New York was a significant organization for bringing health care to the urban poor.

The survey concluded, first, that the state supervision programs were very uneven and often lax, and, second, that the bacteriological quality of the water, particularly among small systems, was of concern.

Researchers told the men they were being treated for "bad blood", a local term referring to several ailments, including syphilis, anemia, and fatigue.

[51] A USPHS physician who took part in the 1932–1972 Tuskegee program, John Charles Cutler, was in charge of the U.S. government's syphilis experiments in Guatemala, in which in the Central American Republic of Guatemala, Guatemalan prisoners, soldiers, orphaned children, and others were deliberately infected with syphilis and other sexually-transmitted diseases from 1946 to 1948, in order to scientifically study the disease, in a project funded by a grant from the National Institutes of Health of the United States in Bethesda, Maryland.

Secretary of State Hillary Clinton apologized to the Republic of Guatemala for this program in 2010, in light of the serious ethical lapses in moral judgement which occurred.