Seeking to increase pressure on McDonald’s, Wendy’s and other fast-food restaurants, organizers of a movement demanding a $15-an-hour wage for fast-food workers say they will sponsor one-day strikes in 100 cities on Thursday and protest activities in 100 additional cities.

As the movement struggles to find pressure points in its quest for substantially higher wages for workers, organizers said strikes were planned for the first time in cities like Charleston, S.C.; Providence, R.I.; and Pittsburgh.

The protests have expanded greatly since November 2012, when 200 fast-food workers engaged in a one-day strike at more than 20 restaurants in New York City, the first such walkout in the history of the nation’s fast-food industry.

“There’s been pretty huge growth in one year,” said Kendall Fells, one of the movement’s main organizers. “People understand that a one-day strike is not going to get them there. They understand that this needs to continue to grow.”