(CNN) What started as a spark this year in Los Angeles is spreading like wildfire across the country.
From California to Denver to Virginia, more teachers are demanding better school funding and higher pay. And they're willing to walk the picket lines to get it.
"We can talk a lot about salaries and resources, but those who face the brunt of the consequence of not having a fully funded public education system are those kids," said Sarah Pedersen, one of the hundreds of teachers who rallied at the Virginia state Capitol on Monday.
The Virginia rally is the first big protest since 30,000 educators in Los Angeles went on strike this month. That strike cost more than $125 million, but led to several victories for teachers and students.
Here's where the new wave of protests are headed:
A sea of red shirts covered the front of the Capitol as teachers chanted a familiar rallying cry: "#RedForEd"
Virginia is the 12th wealthiest state, but its teachers earn less than the national average, according to the Virginia Education Association. And since the Great Recession, state funding for K-12 schools has declined 12% when adjusted for inflation.
While teachers participated in the one-day rally in Richmond, it wasn't a strike. For many schools, classes were already canceled Monday for a professional development day.
But just because Virginia teachers aren't on strike doesn't make their situations less dire, Pedersen said.
"Every year in the winter, we lose heat for a week," the sixth-grade teacher said.
"For the past eight weeks, my classroom has been either below 55 degrees or above 95 degrees because we are located above the boiler. My building is 100 years old. We don't have the resources as a district to replace the boiler."
Last month, Gov. Ralph Northam proposed a budget that would include $268.7 million in new funding for K-12 education. The budget proposal includes an extra 2% raise for teachers, which means teachers would get a combined 5% raise starting July 1.
The proposed 5% raise is now working its way through the state Legislature.
For the first time in a quarter century, Denver teachers are set to strike. We just don't know when.
Last week, 93% of the Denver Classroom Teachers Association approved a strike after negotiations with the school district failed.
The union had been negotiating with the district for 14 months to overhaul the compensation system, which the union says is directly linked to the city's teacher turnover rate.
According to the DCTA, 31% of Denver teachers have been working at their school for three years or less.
The union said its proposal could be funded if some of the $4 million designated annually for administrator bonuses was invested in teacher salaries.
DCTA originally said members could strike as early as Monday, but announced last week that the strike was postponed.
Denver Public Schools said it is "committed to doing everything in our power to prevent a strike."
"In negotiations, DPS added $26.5 million to teacher pay, including an average 10% salary increase for teachers next year, as we worked to find common ground," the school district said.
DPS said the union also made some concessions, reducing its demands by $2.6 million.
"Unfortunately," DPS said, "we were unable to reach an agreement by the deadline, and the union has voted to strike."
Members of the SC for ED advocacy group took personal days off work Tuesday to meet with lawmakers for a "Money Matters Lobby Day."
Teachers want a 10% across-the-board salary increase to get closer to the national average. As of 2017, South Carolina ranked 38th in teacher pay, with an average salary of about $50,000, according to data from the National Education Association.
SC for ED said teachers "are leaving the profession because their salaries are too meager to provide a reasonable standard of living for themselves and their families."
The group is also lobbying for legislation that would prohibit retaliation against teachers for making public policy comments and reduce the amount of standardized testing.
While some state lawmakers have touted House Bill 3759 as a way to improve education, SC for ED said it had many concerns about the bill, including a part that would allow high-performing schools to hire more noncertified teachers, as long as they don't make up more than 25% of the teaching staff.
Members of the Oakland Education Association are voting this week on whether to strike. If they do, it will be another setback for a district that's facing layoffs.
Teachers are demanding smaller class sizes and a 12% increase in teacher pay over the next three years.
They also want more counselors and nurses, so schools can have at least one counselor for every 250 students and at least one nurse for every 750 students.
But the Oakland Unified School District is in a tough financial situation that will require "major budget reductions for the third year in a row," Superintendent Kyla Johnson-Trammell said. "These cuts will include laying off staff."
Still "we are doing everything we can to give our teachers a fair contract that's sustainable for the District," Johnson-Trammell wrote.
After Oklahoma teachers flooded the state capital for nine days last year, a state lawmaker wants to permanently revoke the teaching certificates of anyone who walks out again.
Rep. Todd Russ, who wrote House Bill 2214, said the main point of the bill is to make sure kids don't suffer a disruption in their education.
He told CNN the new bill fixes a loophole in the existing law. It's already illegal for teachers to go on strike in Oklahoma, but Russ' proposal would also make it illegal for teachers to "walk out" like they did last year.
What's the difference between a walkout and a strike?
Hundreds of teachers rallied last year, demanding more school funding and higher raises. Some worked three to six jobs to support their families.
Russ said last year's walkout didn't accomplish anything.
Shortly before the protest, he and other lawmakers already approved some -- but not all -- of the funding requested by teachers. And teachers didn't get any extra funding after their nine-day protest.
But Alicia Priest, president of the Oklahoma Education Association, said she believes lawmakers ponied up some funding only because teachers threatened a walkout.
Pedersen, the sixth-grade teacher in Virginia, said it's increasingly difficult to live on a teacher's salary.
"My husband and I are both public school teachers in Richmond. We both have master's degrees and we have a daughter who is a year and a half years old," she said.
She said the public school insurance is inadequate, so much so that when her daughter was born, "the standard delivery cost me $10,000 in out-of-pocket costs. So, having her cost me $10,000 in medical debt."
Pedersen said even though she loves teaching and loves her school, "we can't make a living this way."
"The teacher walkouts have been happening for decades, which is what leads to the vacancies," she said. "My husband and I will likely be two of them unless something changes fast."