Sara Martín reads bedtime stories with her children. When the kids were younger, she says, staying up to date on their frequent immunizations was tough, because of cost and transportation issues. Lauren M. Whaley/CHCF Center for Health Reporting hide caption

A lynching attended by a large mob. Courtesy of the Library of Congress hide caption

The James C. Nance Memorial Bridge, which connects Purcell and Lexington, Okla., is closed for repair in March 2014. A handful of states have raised their gas taxes in part to fund transportation projects like bridge and road repairs. Sue Ogrocki/AP hide caption

Detroit Prosecutor Kym Worthy talks about the $35 million pledged by the Manhattan district attorney to help eliminate a nationwide backlog in testing rape kits during a news conference in November. Julie Jacobson/AP hide caption

The eruption of Mount Pinatubo in the Philippines in 1991 spewed almost 20 million tons of sulfur dioxide into the atmosphere, causing worldwide temperatures to drop half a degree on average. Arlan Naeg/AFP/Getty Images hide caption

A demonstrator dressed as a bather protests against the rationing of water, outside the official residence of Sao Paulo's Governor Geraldo Alckmin in Sao Paulo, on Jan. 26. The banner behind him reads, "Planet Water, Dry Lives." Andre Penner/AP hide caption

Mary Harris was relieved when Stella was born with a mop of thick black hair, as if she had been protected from the chemo somehow. Courtesy of Howard Harris hide caption

Dallas insurance agent Jo Ann Charron has worked with clients to help clear confusion over subsidies offered by plans on the federal health insurance exchange. This sort of free guidance can save insurance shoppers time and money, agents say. LM Otero/AP hide caption

Comedy Central announced today that Jon Stewart will be leaving The Daily Show later this year. Comedy Central hide caption