Getting a college degree is the new normal.

High schools emphasize the college track to students, economists argue that the jobs of the future will require a college-educated workforce, and President Obama proclaims in his State of the Union address that higher education “is an economic imperative that every family in America should be able to afford.”

But it wasn’t always this way.

Until World War II, less than 15 percent of high school graduates went to college. It was a path largely reserved for the privileged few, mostly white men and mainly families wealthy enough to afford it.

But the GI Bill, aimed at helping the roughly 16 million veterans returning from World War II to re-enter American society, transformed the higher education landscape.

Under the GI Bill, passed in 1944, veterans got free tuition and fees, free books, credit for their wartime experience and a monthly allowance.

It was hugely popular, according to John Thelin, a professor at the University of Kentucky and author of “A History of American Higher Education.”

In the peak year of 1947, veterans accounted for 49 percent of college admissions. By the time the original GI Bill ended in July 1956, 7.8 million veterans had participated in an education or training program.

Colleges went into growth mode, hiring and building facilities to accommodate all the students. Another boost to higher education came in 1947, when a presidential commission issued a report calling for sweeping changes to it – in particular shaping the narrative that an educated citizenry was critical to a democracy.

The Truman Commission Report was a blueprint that called for a vast expansion of the community college system, and laid out the role of the states and the federal government in expanding the existing system and how to handle financial aid.

Thelin said the report became a working guide of sorts for higher education leaders in the 1950s, and had support from both Democrats and Republicans.

“It really was an optimistic and buoyant time,” he said.

The Soviet launch of Sputnik in 1957 influenced federal aid for college students. The National Defense Education Act of 1958 provided low-interest loans for college students, with debt cancellation for those who became teachers after graduation. The law also established graduate fellowships to encourage students in the sciences, mathematics, engineering and other strategic fields.

The Civil Rights Act of 1964 and the Higher Education Act of 1965 also expanded access – by increasing the amount of federal money for universities and providing scholarships and low-interest loans for students – and by the end of the 1960s, more than half of all high school graduates were enrolling in either two-year or four-year colleges.

As the Higher Education Act was renewed over the decades, the federal government added other incentives and benefits for college students, such as the federal Pell Grant system and tuition tax credits.

During the 1960s and ’70s, there was a psychological shift toward imagining that any American should be able to go to college, Thelin said.

But tuition started to increase significantly in the 1980s and ’90s, leading to new pressure on the federal government’s student loan program. The volume of student loans ballooned in the 1990s, when Congress increased loan limits, introduced unsubsidized loans, and increased access to include more middle-class families. Borrowing increased by almost $10 billion from 1992-93 to 1994-95, nearly a two-thirds increase in just two years.

The expectation that high school graduates should go on to college was fueled by the 1983 “A Nation At Risk” report, which said the United States had to be better prepared to compete economically on a global scale – a shift, Thelin said, from the earlier focus on college as a way to instill democratic virtues in the citizenry.

The technology boom in recent decades has only added to the drumbeat emphasizing the need for U.S. students to compete on a global scale with a better educated workforce. Beyond that, studies have shown for decades that workers with college degrees earn higher salaries, are less likely to be unemployed and have more career mobility.

That pressure to get a college degree comes with its own backlash. This year, the Portland School District, the largest in the state, tried to make applying to college a requirement for getting a high school diploma. After strong objections from parents, the school board removed the language from the final requirements.

Today, 66 percent of high school graduates nationwide go on to college, according to federal labor data. In Maine, that percentage was 62 percent for the class of 2013, up from 57 percent for the class of 2006, according to the Mitchell Institute.