Former Maryland House speaker R. Clayton Mitchell Jr., right, served more than 20 years in the House of Delegates. (Barbara Haddock Taylor/Baltimore Sun)

R. Clayton Mitchell Jr., a conservative Democrat and longtime member of the Maryland House of Delegates who served six years in the 1980s and 1990s as House speaker and was a loyal ally of then-Gov. William Donald Schaefer, died June 13 at his home in Kennedyville, Md. He was 83.

The cause was adenoid cystic carcinoma, a form of cancer, said a son, Chris Mitchell.

Mr. Mitchell, who was known as Clay, was a lanky farmer and businessman who lived most of his life on Maryland’s rural Eastern Shore. First elected to the House of Delegates in 1970, he became the speaker in 1987, at a time when both branches of the legislature and the governor’s mansion were under new leadership.

Schaefer, a colorful former Baltimore mayor, was elected governor in 1986 and threw his support behind Mr. Mitchell as a consensus-builder who could lead the often-fractious House of Delegates during the session beginning in January 1987. The same year, Thomas V. Mike Miller Jr., a Prince George’s County Democrat, took over as president of the Maryland Senate — a position he still holds today.

Mr. Mitchell’s task was to manage the varied political whims and egos of the 141 members of the House of Delegates.

“It takes a while for people to develop loyalties to you,” Mr. Mitchell said when he was elected speaker. “I have to prove to them that I have the leadership abilities.”

Mr. Mitchell in 1987. (Maryland State Archives)

Despite Schaefer’s sometimes irascible comments about Mr. Mitchell’s native Eastern Shore — which he once likened to an outhouse — the two put up a united front in passing legislation and in cutting the state budget at a time of declining revenue.

Mr. Mitchell was “known for his withering gaze from the speaker’s rostrum and for running the 141-member chamber with an iron hand,” according to a Washington Post story from 1993. Legislators quickly learned not to challenge his authority.

If members of his party failed to fall in line or violated long-held legislative customs, he did not hesitate to strip them of committee chairmanships or other leadership positions.

In 1989, freshman Del. Peter Franchot (D-Montgomery) sponsored a bill to restrict the sale of military-style assault weapons and sought to display several of the weapons at a news conference. Although the weapons were in the custody of police officers, Mr. Mitchell was furious that Franchot had not told him of his plans.

Bursting into Franchot’s office, he had all the rifles and police officers removed and gave Franchot a stern lecture. When asked whether he was “livid,” Mr. Mitchell replied, “That’s an adequate word. But if there was one higher than that, you could use that instead.”

Mr. Mitchell advanced the political career of Baltimore’s Elijah E. Cummings (D), now a member of the U.S. House of Representatives, by naming him Maryland’s first African American speaker pro tem. But some female and black legislators accused Mr. Mitchell of being insensitive to their concerns.

In 1990, he removed Prince George’s County Del. Juanita D. Culbreath-Miller (D) from a committee assignment after she ignored his orders not to allow a gospel choir to sing in the House chambers in observance of Martin Luther King Jr.’s birthday. The rules allowed no outside performances in the House, Mr. Mitchell said.

With his experience in farming and real estate, Mr. Mitchell was often skeptical of what he saw as onerous environmental regulations. During the 1990 legislative session, he delayed a bill to require developers to plant trees that had been had cut down to make way for housing.

When the session ended, without the bill advancing to the Senate, one of its sponsors — Sen. John A. Cade (R-Anne Arundel) — charged Mr. Mitchell with “misfeasance, malfeasance and every other kind of feasance.”

In 1991, Mr. Mitchell was cleared by state and federal investigators of wrongdoing in connection with a real estate deal he made with harness-track owner Mark Vogel. Critics charged that Mr. Mitchell had helped engineer tax breaks for Vogel, once dubbed the Donald Trump of Prince George’s County.

Reelected five times without opposition, Mr. Mitchell was seemingly secure in his powerful position and was considering a run for governor when he abruptly resigned in November 1993. Earlier that year, he faced criticism after he personally lobbied for a bill that would have benefited the business interests of one of his sons.

Roy Clayton Mitchell Jr. was born April 16, 1936, in Chestertown, Md., and grew up on his family’s farm in the nearby community of Kennedyville. He served in the Army and attended Goldey-Beacom College in Delaware before returning to his native Kent County. He served on the county commission before he was elected to the state legislature.

Mr. Mitchell did not seek public office after leaving the House of Delegates. He owned an electronics store and worked in real estate and served on the governing board of Washington College in Chestertown.

His wife of 59 years, the former Marie Mathilde “Teel” Whitsitt, died in 2017. Survivors include three sons, Clayton A. Mitchell of Stevensville, Md., John Christopher “Chris” Mitchell of Kennedyville and Michael R. Mitchell of Dover, Del.; six grandchildren; and two great-grandchildren.

Mr. Mitchell seldom spoke in public about the stress of his years as speaker, but in 1990 — while trying to manage the legislature while he was under federal investigation — he said, “Walk in my shoes for nine months and see how you like it.”

An earlier version of this story incorrectly stated that Mr. Mitchell was born in 1939. He was born in 1936.