Why the increase in usage of the word "quarantine" between around 1880 and 1930?

The spike in usage of the term quarantine appears to be related both to importation of contagious diseases because of the increase of immigration the late 19th century and to the many different health organizations at local and state levels which adopted quarantine as a measure to prevent the spread of diseases. The system was nationalized a few decades later and with it immigration began to slowdown

When the United States was first established, little was done to prevent the importation of infectious diseases. Protection against imported diseases fell under local and state jurisdiction. Individual municipalities enacted a variety of quarantine regulations for arriving vessels.

State and local governments made sporadic attempts to impose quarantine requirements. Continued outbreaks of yellow fever finally prompted Congress to pass federal quarantine legislation in 1878. This legislation, while not conflicting with states’ rights, paved the way for federal involvement in quarantine activities.

Outbreaks of cholera from passenger ships arriving from Europe prompted a reinterpretation of the law in 1892 to provide the federal government more authority in imposing quarantine requirements.

The quarantine system was fully nationalized by 1921 when administration of the last quarantine station was transferred to the federal government.

The Public Health Service Act of 1944 clearly established the federal government’s quarantine authority for the first time. The act gave the U.S. Public Health Service (PHS) responsibility for preventing the introduction, transmission, and spread of communicable diseases from foreign countries into the United States.

History of Quarantine