The cheerful pastel colors of Rainbow Row, a famous block of Colonial-era townhomes on East Bay Street, have infected nearby buildings.

While the original row has been defined traditionally as the buildings on the west side of East Bay between Elliott and Tradd streets, there are now similarly colorful structures to the immediate north and south, and they're also creeping through Tradd to the west. 

"Color is contagious," said Kristopher King, the executive director of the Preservation Society of Charleston. 

But the expansion of color is also in keeping with the creation of the modern Charleston icon, which, in its current form, dates only to the first half of the 20th century, not the city's earliest days.

The buildings were originally commercial storefronts, a relatively prosperous area when the the city's waterfront was along East Bay.

As land along that edge of the peninsula was filled in, most shipping moved north and the area's fortunes turned after the Civil War. The old block gradually became a slum, with impoverished people living above the stores. 

There was "not just a family in every house, but a family living in every room of every house," according to a 1973 News and Courier interview with Dorothy Legge, who bought the house that spanned the addresses from 99 to 101 East Bay St.

When she bought it in 1931, the structure still housed a supply store for ships.

Legge was the first to re-paint a home on the street with the hues that are so famous today. She told the newspaper she wanted to uplift the area "with a pretty color, and I had it painted this sort of peachy pink."

Robert Stockton, a College of Charleston historian who has researched hundreds of the city's oldest buildings, said the renovations of the 1930s were an example of a phenomenon the city is still grappling with today: gentrification. 

Indeed, Legge, the wife of S.C. Supreme Court Justice Lionel K. Legge, said in 1973 that the neighborhood was mostly tenement housing for black residents when she arrived there. 

Legge not only restored a home there, but she also was crucial in convincing her friends, including preservation pioneer Susan Pringle Frost, to buy and fix up some of the other houses nearby.

By 1936, "Rainbow Row" had become the unofficial name for the street, according to an article in November of that year in The News and Courier.  

The period marked an era of reinvestment in Charleston, King said, the same period in which there was a boom in the city's cultural scene known as the Charleston Renaissance. 

The national context also supported that economic development, Charleston County Public Library historian Nic Butler said. The Federal Housing Administration was created as a part of the New Deal in 1934, and helped to finance home purchases. The federal and local governments were encouraging residential redevelopment, and Charleston officials said at the time that the city had a housing shortage. 

"The government is encouraging people to invest in real estate, real estate is a safe investment, that’s where you need to put your money if you have any in this Depression," Butler said. 

Legge's home was a prime example. 

"The Legge project on East Bay Street gets referred to multiple times as an exemplary project," Butler said. "One of the reasons that name Rainbow Row became so popular, for one thing it's right on the waterfront, tourists are driving right by it, but also it was a very visible success story."

Indeed, many found a pot of gold at the end of its restoration.

In strict preservationist terms, the renovation work likely would not have passed muster under modern rules, both King and Stockton said, because many owners replaced the original storefronts with carriage gates. The city's current Board of Architectural Review likely would say "nay" to that today. 

But the section of street has nonetheless become iconic, so it's not surprising that the lively shades of Rainbow Row continue to spread, King said. 

"That's kind of Charleston's approach to preservation ... one homeowner at a time, and then all of a sudden after a few decades of progress, you can kind of step back and see the sum total of the individual efforts," he said. 

When a house is occasionally repainted in a new hue, however, it causes significant agita to the local arts community, King said. Suddenly, their drawings, paintings and photographs of the street are out of date. 

Today, the block remains a very popular spot for tourists, and Stockton said it's also a subject of several myths spun by some tour guides. 

For example, the different colors are not, and never were, a kind of code for illiterate Charlestonians to tell which building housed which type of craftsman or merchant. 

"It's baloney," Stockton said.

Reach Chloe Johnson at 843-735-9985. Follow her on Twitter @_ChloeAJ.