The Centers for Disease Control and Prevention’s (CDC) most recent reporting on measles in the United States shows that 1,044 cases are documented in 28 states — the highest rate of infection since 1992 and a profound shift from a disease that was eliminated across the country in 2000.

The CDC said the reasons for the measles outbreak are people traveling to other countries and bringing the virus back into the U.S. and populations in the U.S. that are not vaccinated.

Measles and chickenpox have also been reported in the populations of immigrants from Central America and other countries that lack vaccination programs and who are coming across the U.S. border with Mexico in record numbers.

PBS reported a timeline of measles history in the United States and how and why the disease has come roaring back:
•In 1657, a merchant in Boston records the first outbreak of measles.
•In 1861, 67,000 Union troops in the Civil War contract measles; 4,000 died.
•In 1912, the government requires U.S. health care providers and laboratories to report measles cases, and in the first decade of reporting, deaths from the disease range from 4,700 to 14,500 per year.
•In 1958, the U.S. records the largest number of measles cases in a single year, with 763,094 cases reported. That same year scientists started working on a measles vaccine.
•In 1963, the first measles vaccine is licensed and used, and the rate of infections in the next five years drops 96 percent, from 385,000 to 22,000.
•In 1971 the measles, mumps, and rubella vaccine is introduced and replaces the measles vaccine.
•In 1998, a British researcher published a now-discredited paper connecting the MMR vaccine to autism — a report that got widespread attention and led to the anti-vaccination movement that continues to this day and is contributing to the current outbreak.
•In 2000, measles is declared eliminated from the U.S., which meant that continuous transmission across the country had not occurred for more than 12 months.
•In 2011, measles cases surpass 200 for the first time since 2000