“My art do my talking,” said Mr. Dial. (Matt Arnett)

Thornton Dial, a sharecropper’s son who for decades spent his spare time soldering scrap metal, animal bones and other found objects into representations of black life in America — creations that were eventually recognized as artwork worthy of inclusion in the most prestigious museums of the United States, died Jan. 25 at his home in McCalla, Ala. He was 87.

A son, Richard Dial, confirmed the death and said he did not know the cause.

Mr. Dial was untrained as an artist but by the end of his life saw his sculptures and paintings housed at institutions including the Metropolitan Museum of Art and the Museum of Modern Art in New York, the Smithsonian’s American Art Museum in Washington, and the Museum of Fine Arts in Houston.

He would have struggled to read the critical reviews favorably comparing his work to the artistry of Jackson Pollock and Anselm Kiefer. Mr. Dial’s formal education ended in early elementary school, and he was largely illiterate.

He rarely strayed from his home in Alabama, where he lived for decades under Jim Crow segregation, earning a livelihood at the Pullman Standard boxcar company, pouring concrete, laying bricks and raising livestock.

Mr. Dial died Jan. 25 at 87. (Matt Arnett)

He never visited a museum before the 1980s, when William Arnett, a patron of African American artists and collector of so-called outsider art, happened upon the assemblages stored in Mr. Dial’s garage. Mr. Dial had buried other pieces in the ground, partly in shame of his unusual creations.

With materials consisting of spray paint, rebar, barbed wire, tree branches, rags and other discards of life, Mr. Dial created hundreds of works recognized for their stunning originality.

“I mostly pick up stuff,” he told the New York Times in 2011. “I start on a picture when I get a whole lot of stuff together. And then I look at the piece and think about life.”

In “High and Wide (Carrying the Rats to the Man)” (2002), a 6-by-11-foot construction made from materials including goat hides, carpet, found metal and spray paint, he chained a Mickey Mouse toy, its eyes blank and face darkened, to a ship in an unsparing representation of the exploitation of slavery.

“The allusion to the transatlantic slave trade is clear,” crystal am nelson, a scholar of African American art, wrote in the online journal Art Practical, “but by using Mickey Mouse in place of an African American figure, Dial exposes the absurd fiction that justified the New World slave trade.”

Graveyard Traveler/Selma Bridge” (1992), a canvas-on-wood creation made with carpet, burlap, paint-can lids, pinecones, a plastic hose and other supplies, depicted the 1965 civil rights march in Selma, Ala., where state troopers and vigilantes set upon protesters with tear gas and billy clubs.

Mr. Dial often used the figure of a tiger to portray the African American struggle. In one work, he assembled discarded clothing, branches and a pair of boots to create what he said was a representation of President Barack Obama crossing a jungle unscathed.

Mr. Dial might have remained undiscovered if not for an encounter with another Alabama artist, Lonnie Holley, in the 1980s. Holley introduced Mr. Dial to Arnett, who was impressed by Mr. Dial’s life-size metal sculpture of a turkey.

When Arnett asked to purchase the piece, Mr. Dial proposed a price of $20. They agreed on $200, Mr. Dial’s first sale.

Arnett became Mr. Dial’s patron, providing him with a regular stipend and supplies in exchange for the right to purchase his artwork. Their partnership was scrutinized in a 1993 CBS “60 Minutes” report by Morley Safer questioning the relationship between “black, uneducated, poor and talented” artists and dealers who were “white, sophisticated and well off.”

Mr. Dial defended Arnett, telling the Times that they had “traveled together” since their first meeting. “I had no dealings with any other white man before I met him,” Mr. Dial said.

In an interview with The Washington Post on Wednesday, Mr. Dial’s son expressed his appreciation for Arnett, who he said had “opened the doors to the art world” for his father, a moment Mr. Dial “had been looking for all his life.”

Promoted by Arnett, Mr. Dial’s works eventually fetched tens, sometimes hundreds of thousands of dollars at auction, their value stemming in part from his creativity.

“I’d never seen any artist’s works,” Mr. Dial told the Times in 1997. “I can’t copy off anybody because it’s something I do my own self.”

Thornton Dial was born to a large family in Emelle, Ala., on Sept. 10, 1928. He did not know his father, and his mother was a sharecropper. He was raised by a great-grandmother and other women in his family.

He was 13 when he enrolled in second grade, where he said he was mocked for his size.

“I didn’t know nothing, hadn’t been to school much, was more a man than a schoolboy,” he said in an oral history published in the volume “Souls Grown Deep: African American Vernacular Art” by William and Paul Arnett. “They told me, ‘Learn to figure out your money and write your name: That’s as far as a Negro can go.’ ”

From a young age, he worked with his hands to create things of utility and beauty. He made dolls from cornstalks and said he practiced drawing not with crayons, but with wires in the sand.

He found work, although not gainful employment, at the boxcar company. After his retirement, he built garden furniture while making his art. He lived to see his works featured in solo exhibitions at galleries in New York and at museums around the country.

His wife, the former Clara Murrow, whom he married in 1951, died in 2005. Their daughter, Patricia Dial, who had cerebral palsy, died in 1987. Survivors include four children, Thornton Dial Jr. and Mattie Dial, both of McCalla, and Richard Dial and Dan Dial, both of Bessemer, Ala.; a half-brother; a half-sister; and numerous grandchildren and great-grandchildren.

Mr. Dial said that he knew some people considered him “too ignorant for art.”

“Seem like some people always going to value the Negro that way,” he told Arnett in an interview once cited by the New Yorker magazine. “I believe I have proved that my art is about ideas, and about life, and the experience of the world. . . . I ain’t never been much good at talking about stuff. I always just done the stuff I had a mind to do. My art do my talking.”

The photo captions in an earlier version of this article incorrectly identified Mr. Dial as Mr. Arnett. The captions have been corrected.