Before Whitney Houston made “I Will Always Love You” her signature ballad, another artist used it as a declaration of independence.

In 1973, Dolly Parton was enjoying modest chart success but still found herself shackled to Porter Wagoner, the artist who had showcased her on his TV show — and then refused to let her go.

As Parton recalls in “Country Music,” the addictive docuseries premiering Sunday, she wrote the song one night as both a kiss-up to her mentor and a plea to let her out of their contract.

It worked.

The 16-hour film is jam-packed with such colorful anecdotes, including Webb Pierce peddling Mason jars filled with water from his guitar-shaped pool, a young Merle Haggard busting out of juvenile detention 17 times and a desperate Willie Nelson selling the rights to “Night Life” for $200.

But Parton’s story best represents director Ken Burns’ not-so-secret agenda: to honor those marginalized in standard history books.

In the case of “The Mayo Clinic,” “Baseball,” “Prohibition” and now, “Country,” that would be women and minorities.

It’s easy to ignore their contributions during a decade in which good ol’ boys obsessed with drinking beer and driving pickup trucks dominate the radio airwaves.

And nothing in the series, running in two-hour blocks over eight nights, will dissuade you from voting for Bill Monroe, Hank Williams and Jimmie Rodgers to be represented on country’s Mount Rushmore.

But it’s clear early on that Burns also would insist on carving out space for Maybelle Carter, who Vince Gill hails in the film as “maybe the most iconic instrumentalist we’ve ever had.”

Listening to her develop her “scratch” style of guitar playing is as mind-blowing as Jimi Hendrix tearing up “The Star-Spangled Banner” at Woodstock.

Other goose-bump moments include watching 12-year-old Brenda Lee belt out “Dynamite” like she was possessed by a 60-year-old gospel singer; George Jones and Tammy Wynette making the best use of their marital differences in “We’re Gonna Hold On”; and Loretta Lynn reminding listeners not to come home a-drinkin’ with lovin’ on your mind.

The stories resonate just as much.

You’ll cringe when hearing how Jeannie C. Riley was forced to wear a miniskirt and go-go boots to accept an award for her liberation song “Harper Valley P.T.A.,” giggle at sophisticated Sarah Cannon adopting the persona of the cheerful bumpkin Minnie Pearl and melt over the details of Patsy Cline’s fatal plane crash.

You’ll also learn about artists who never got their due, most notably Rodgers’ co-songwriter Elsie McWilliams and Felice Bryant, who along with her husband, Boudleaux, penned 99 songs, pitching many of them over spaghetti dinners.

“If you wanted superstrong women telling amazing stories, you went to country,” says artist Rhiannon Giddens, one of four black artists offering commentary, the other three being Wynton Marsalis, Hootie and the Blowfish’s Darius Rucker and Charley Pride.

At first glance, that number may seem high. But time and again Burns points out how country pioneers like Monroe, Rodgers and Johnny Cash all were influenced by black artists in their youth.

Nelson goes so far as to call Ray Charles’ “I Can’t Stop Loving You,” the first single from his groundbreaking 1962 album, “Modern Sounds in Country and Western Music,” the “biggest thing that one artist has ever done for country music.” (The special, “Opry Salutes Ray Charles,” airs at 2 p.m. Sunday on TPT Life.)

Burns also makes room for largely forgotten contributors, like harmonica player DeFord Bailey, the first black artist to be featured on the Grand Ole Opry stage, and Johnny Rodriguez, one of the few Latin American stars to ever make a dent on the country charts.

The goal of being all-inclusive is commendable — and also exhausting. Some of the artists whiz by faster than a hiccup in Jones’ “White Lightning.”

In fact, it’s hard to think of a significant artist from 1923 to 1996, the period covered in the film, that doesn’t get at least a few seconds in the spotlight — although those who leaned toward soft rock are not always treated with reverence.

Burns delivers one of his rare low jabs by featuring video of Charlie Rich announcing from the podium that John Denver had just won CMA’s Entertainer of the Year Award while setting fire to the card with his name on it.

But Denver’s legacy will hold up just fine without Burns’ stamp of approval. Those who will really get a boost are the names that need it most.

In Sunday’s premiere, Kathy Mattea recalls admiring Thomas Hart Benton’s “The Sources of Country Music,” during her stint as a tour guide at Nashville’s Country Music Hall of Fame and Museum.

Tex Ritter is the painting’s prominent figure, but he’s surrounded by a diverse cast, including a black banjo player and female dulcimer players.

“It’s so colorful,” Mattea says. “There’s so much energy to it.”

The same could be said for Burns’ latest masterpiece.