Links to the above songs:
Martina McBride - Independence Day
Garth Brooks - We Shall Be Free
Reba McEntire - The Night the Lights Went Out in Georgia (this is a cover--the original was performed by Vicki Lawrence)
Kacey Musgraves - Follow Your Arrow
The Chicks - Goodbye Earl
Johnny Cash - Man in Black
Some more, since I'm a country fan:
Johnny Cash - The Ballad of Ira Hayes ; tells the story of WWII veteran Ira Hayes, the discrimination he faced in the army, the issues faced by his tribe (starvation, dehydration)
Reba McEntire - Fancy ; another cover, original done by Bobbie Gentry ; about a poor sex-worker who changes her own life, gets herself out of poverty, and eventually out of sex-work
Loretta Lynn - The Pill ; song about birth control and women's reproductive rights
Golden Highway & Molly Tuttle - Side Saddle ; talks about issues women face in the country music industry, as well as double standards
Jason Isbell and the 400 Unit - White Man's World ; discusses white man privilege, fears for his own daughter, how everyone else's struggles are just as important as your own, how people should invest themselves in other peoples wars (aka struggles)
Jason Isbell and the 400 Unit - Last of My Kind ; discusses social isolation, how it can lead to hatred and discrimination. Jason Isbell is also well-known left-winger, advocating for police reform, gun control, and expressing support for LGBT and transgender rights.
Miranda Lambert - Gunpowder and Lead ; a woman finally takes matters into her own hands and murders her abusive partner
Johnny Cash - One Piece of a Time ; a man working on a cadillac assembly line steals car pieces every day in his lunch box so he can, eventually, put it all together and own a card that he could never afford
Maddie & Tae - Girl in a Country Song ; song about misogyny in country music, men's expectation of women
Randy Travis - Three Wooden Crosses ; a farmer, a teacher, a preacher, and a hooker are on a bus searching for different things when a bus accident seemingly kills all aboard ; discussion of faith, kindness towards strangers, the impact you have on the people you leave behind