In 2013, Mississippi ranked dead last in babies who were ever breast-fed, with just 50.5 percent, the Centers for Disease Control reports. Yet the most recent statistics, for 2014, show a big boost—up to 61.5 percent, a vast improvement that puts the state ahead of Louisiana and Kentucky.

Though efforts encouraging mothers in Mississippi to at least start breastfeeding are clearly having some success, most mothers here don't stick with it, and the state still has the lowest rates in the country of breast-fed babies at both six and 12 months. Elsewhere in the U.S, though, breastfeeding has become the norm—as it was more than 100 years ago.

At the turn of the last century, some infants were fed by "wet nurses"—lactating women other than their mothers—and a few were given concoctions made from cows' milk, according to Gabrielle Palmer's 2011 book, "The Politics of Breastfeeding." But most American babies breast-fed for at least a year. That gradually changed, as several companies began selling and aggressively marketing infant formula.

At first, formula was a high-end product used mostly by wealthy women. By 1930, though, most mothers were using formula at some point and only about half of American babies were initially breast-fed. By 1950, just a quarter were, and by 1972 only 22 percent of babies were breast-fed.

The downward trend was broken by an international campaign against formula makers, which activists held responsible for high rates of death among bottle-fed babies. They described an industry that created a need for its product by satisfying a baby's appetite early on, which decreases the baby's interest in the breast and signals to the mother's body to decrease milk production. Families thus became dependent on formula, an expensive product that, as mounting evidence would show, was inferior to breast milk.

A 1974 British expose titled "The Baby Killer" helped turn the tide of public sentiment and spur the boycott of Nestle, one of the biggest formula makers at the time. The piece focused on the health effects of formula use, which were worse in developing countries, where a lack of refrigeration and clean water caused diarrhea and other infections. (The boycott was officially suspended in 1984, after Nestle agreed to follow an international marketing code endorsed by the World Health Organization. But, there is recent evidence that Nestle and other formulas still engage in questionable marketing practices abroad)

Formula-related health problems were significant in the U.S., too. In 1979, in a middle-class U.S. suburb, medical costs for formula-fed babies were 15 times those for breast-fed babies, according to the Palmer book. Mead Johnson, maker of Enfamil, didn't return calls for comment on this story, but says on its website that "the product has undergone several significant reformulations" since it was introduced in 1959, and " is formulated to provide optimal nutrition and to support brain development."   As evidence of the health advantages of breast milk mounted, breastfeeding rates began to creep back up nationwide, a process that's still underway. By 1980, 54 percent of American women initiated breastfeeding. By 1995, 60 percent of new mothers were at least starting to breastfeed.

According to 2014 data from the Centers for Disease Control, 79 percent of new mothers in the U.S. begin breastfeeding, and 27 percent are still breastfeeding a year later. These days, in the U.S. at least, formula doesn't pose the dangers it once did. "Here we have the luxury of having clean water, so formula is a safe option," says Rebecca Seigel, a family physician who encourages her patients to breastfeed when possible. Still, says Seigel, "for many women who can't or choose not to breastfeed, formula can be a reasonable and healthy choice."

Mississippi rates seem to be on their way back up, too. But, as Charlene Collier, prenatal consultant to the Mississippi State Department of Health points out, catching up with the rest of the country won't be easy.

"The work has to start prenatally," Collier says. "It has to start culturally and it has to change the perceptions of breastfeeding in general."