Merle Haggard, who has died aged 79, was one of the most resonant figures in country music for almost half a century. Popular, successful, highly influential upon the genre and critically admired both within and beyond it, he also acquired the status of a spokesman for his core audience, his songs Okie from Muskogee and The Fightin’ Side of Me appearing to rally blue-collar Americans round Old Glory and old-fashioned values. But Haggard was an altogether more complicated and interesting man than that status might suggest.

His family background was an archetypal Dust Bowl story. In 1934, James Haggard and his wife Flossie Mae (nee Harp), like the Joads in John Steinbeck’s The Grapes of Wrath, quit the worn-out soil of Oklahoma to find work in California. They lived in migrant workers’ camps and, when Merle was born after three years, their home in Oildale, near Bakersfield, was a converted railway boxcar. James died when Merle was nine, and five years later the restless youth left home to become an itinerant worker and petty criminal. These early years of poverty and frustration, punctuated by spells in reform school, would inspire some of his most enduring songs, such as Hungry Eyes, Branded Man and Mama Tried.

Facebook Twitter Pinterest Merle Haggard performing The Fightin’ Side of Me

Following a conviction for burglary, Haggard spent his 21st birthday in the state prison at San Quentin, north of San Francisco. Paroled in 1960, he was determined to become a country singer like his models Lefty Frizzell and Jimmie Rodgers, and learned his craft in the bars of Bakersfield. From Frizzell in particular, he absorbed the vocal slides and the wry, resigned blues delivery of the honkytonk singer, a label that came from those bars. For a while he played bass in a band led by Wynn Stewart, a talented, almost forgotten singer who also had some part in moulding the younger man’s style.

He made a few recordings for a small label and began singing with Bonnie Owens, the ex-wife of California’s leading country artist, Buck Owens. In 1965 they married, Haggard’s first marriage, to Leona Hobbs, having ended in divorce. He formed a band, the Strangers, and signed with Capitol Records.

Facebook Twitter Pinterest Merle Haggard and Bonnie Owens performing Slowly But Surely

That year he won an Academy of Country Music award as most promising newcomer and, for three years running, he and Bonnie were voted best vocal duet. By the late 60s, his folio packed with songs like Sing Me Back Home and Today I Started Loving You Again, Haggard was a nationally known artist, winning awards, guesting on TV shows and spearheading the “Nashville West” movement, centred in Bakersfield, which offered a less ingratiating kind of country music than the smooth productions emanating from Nashville itself. He was admired even by artists of a very different stripe, such as the Grateful Dead and Joan Baez, who both recorded Mama Tried and Sing Me Back Home.

Then, in 1969, came Okie from Muskogee, a litany of anti-hippie putdowns celebrating the Oklahoma town “where even squares can have a ball”. It was written in the band bus on the spur of the moment, and when it was recorded, one of the session musicians remembered, everyone was laughing so much that they despaired of getting the job done. But many conservative small-town Americans heard it as a fanfare for the common man, and the album of the same name was his first to sell a million.

When Haggard followed it in 1970 with The Fightin’ Side of Me, an aggressive paean to patriotism, he accrued the kind of admiration that would now be accorded to a rightwing talkshow host. He was invited to play at the White House for President Nixon, who told him he approved of his song Workin’ Man Blues.

Facebook Twitter Pinterest Merle Haggard performing Sing Me Back Home

Unfortunately, Haggard’s broad-brush political gestures obscured other, more finely crafted recordings that reveal much more about the man who made them and the place he wished to occupy in the grand narrative of country music. In 1969, he had also released Same Train, a Different Time, an album of songs associated with Rodgers. A year later, he made a similar tribute to another venerated artist, the western swing bandleader Bob Wills, for which he taught himself to play fiddle. Four years after that he produced Wills’s final album, For the Last Time.

The respect for country music’s history evinced by these projects was both genuine and informed. For the Wills tribute, Haggard recruited former members of Wills’s Texas Playboys, including fiddler Johnny Gimble and guitarist Eldon Shamblin, who continued to play in the Strangers. Another significant sideman was the guitarist Roy Nichols, a veteran of the west coast country music scene, who served in the Strangers for more than 20 years, a period in which they were voted touring band of the year by the Academy of Country Music an unprecedented eight times.

Facebook Twitter Pinterest Merle Haggard and Willie Nelson performing Pancho and Lefty

Other projects, such as a gospel album shared with members of the Carter Family and a venture into Dixieland jazz, attested to Haggard’s inventiveness. Meanwhile, he continued to provide his hardcore followers with memorable country songs like It’s Not Love (But It’s Not Bad) and If We Make It Through December. In 1977 he was elected to the Nashville Songwriters’ Hall of Fame, in the company of another Okie composer, Woody Guthrie. The following year he and Owens were divorced and he married one of his backing singers, Leona Williams. In 1981 he published an autobiography, Sing Me Back Home.

Though periods of his life were marked by heavy drinking, and by songs about it such as The Bottle Let Me Down and I Think I’ll Just Stay Here and Drink, Haggard relaxed only with friends and his band. He had no interest in the social circles of country music, or in spending time with politicians, journalists and other hangers-on; all he really wanted to do, he said, was fish and write songs. In the 80s, now wealthy enough to do that, he worked only on projects that interested him, such as duet albums with George Jones and Willie Nelson; Pancho and Lefty (1983), with Nelson, was another million-seller. During the farming crisis of the mid-80s he produced the sombre Amber Waves of Grain, and in 1987 he regrouped with Bonnie Owens and old friends for the album Chill Factor. By then he had scored 38 No 1 records in the country singles charts.

He was less productive in the 90s and seemed to be settling into the role of living legend, a stature recognised by election to the Country Music Hall of Fame in 1994. But in 2000 he started making albums again and, in Roots, Vol 1, returned to honouring predecessors like Frizzell and Hank Williams. He too was receiving respectful nods from younger artists, being mentioned by name in songs by George Strait, the Dixie Chicks and Brooks & Dunn (“Turn off that rap and play me some Haggard”). His 2005 album Chicago Wind was notable for the song America First, reflecting national disillusion with the Iraq war.

Facebook Twitter Pinterest Merle Haggard and George Jones performing The Way I Am

If he attracted less attention in his later years than certain contemporaries, it was largely because he did not court it. In some ways he could not: as a personality, on stage or TV, he was less immediately striking, less magnetic than, say, Johnny Cash, even though he was a far more gifted singer. His place in country music as a singer and stylemaker is assured, but he himself wished to be remembered, as he once told the journalist Paul Hemphill, “as a writer, somebody who did some living and wrote songs about what he knew. That’s all.”

In November 2008, he was diagnosed with a form of lung cancer and underwent surgery, but by January 2009 he had recovered enough to give concerts again. In 2014–15 he kept up a touring schedule that would have taxed a much younger man. During 2015 he released his last albums, collaborations with fellow veteran country singers Mac Wiseman and Willie Nelson.

Haggard’s marriages to Leona Williams and then Debbie Parret ended in divorce. He is survived by his fifth wife, Theresa Lane; their two children, Ben and Jenessa; four children, Dana, Marty, Kelli and Noel, from his first marriage; a son, Scott, from another relationship; and a sister, Lillian.

• Merle Ronald Haggard, singer and songwriter, born 6 April 1937; died 6 April 2016