The files cover the first eight months of Thatcher's 11½ years as prime minister, giving glimpses of her embarking on an ambitious domestic agenda to revive the economy and curb the unions, and engaging with the Soviet invasion of Afghanistan and the seizure of the U.S. Embassy in Tehran on Nov. 4.
They were made public by the Thatcher Foundation under rules that allow for keeping documents secret for 30 years.
On Nov. 14, Mr. Carter asked in a cable for "the strongest possible remonstration or action" to pressure Iran, suggesting that Britain consider reducing the number of diplomatic staff in the country.
Thatcher responded a week later that Britain had withdrawn some staff, "but we have not hitherto believed it wise to make a political point of any reduction, partly because we doubt whether the Iranians would be much impressed and partly because of the risk of retaliatory action against those remaining."
In May, before the embassy seizure and less than two weeks after Thatcher was elected, Mr. Carter appealed for "urgent private representations" to Iranian authorities to assure the safety of Iranian Jews. Thatcher refused, saying the British Embassy did not believe Jews faced organized persecution, and that intervention "could indeed make their position less secure."
Thatcher had met Mr. Carter twice in 1977, before she was elected, and the U.S. president came away displeased, though according to previously released papers, he mellowed by the time Thatcher became prime minister, agreeing with National Security Adviser Zbigniew Brzezinski's view that she was "a cooler, wiser, more pragmatic person now than the opposition leader you met in May 1977 or the dogmatic lady who visited you in Washington that fall."
The newly released files - 23,198 pages from Thatcher's personal and political files - show touches of "the Iron Lady" even before she became Britain's first female prime minister in 1979.
In 1977, in a reply to a consultant, she wrote: "I have already come to the conclusion that I shall have to take most of the major decisions myself."
That steeliness revealed itself in trivial matters too, such as putting her image on commemorative teacups. "No (underlined) permission to be given at all on any grounds of any kind," she replied to the adviser who suggested it.
(She apparently softened with time: A limited-edition Royal Worcester crockery set appeared in 1989.)
Many of the papers go online Saturday at the Thatcher Foundation Web site and many of them duplicate official government documents in the National Archives. Chris Collins, editor of the Web site, hopes that all 1 million pages, both from the National Archives and her personal files, could be digitized and many of them put online.
In her first days in power, Thatcher's office was swamped with congratulatory letters and telegrams from well-wishers including the late romantic novelist Barbara Cartland, singer Petula Clark, American economist Milton Friedman and German Chancellor Helmut Kohl. A slightly garbled telegram from an excited British Davis Cup tennis team said: "BALL NOW IN YOUR COURT TO SERVE CONNOWBALLS TO UNIONS."
That's what Thatcher's supporters expected of her: to tame the trade unions which they blamed for Britain's economic malaise of the 1970s.
News that she was to be honored with an award from the World Government of the Age of Enlightenment - followers of the Maharishi Mahesh Yogi, the Beatles' guru - flummoxed her advisers.
"The Age of Enlightenment appears to be a somewhat eccentric religious movement which is exceptionally well endowed," aide Tony Butler wrote. "We know nothing of its funding or of its aims or objectives, though we think from the extravagant language in which these are couched that it would be prudent to view them with at any rate some suspicion."
On Dec. 18 Butler drafted letters of acceptance and refusal - "I cannot say that either is entirely satisfactory," he noted - and asked Thatcher to choose.
Thatcher, perhaps feeling trapped by bureaucratic delay, noted: "As it is to be awarded Dec. 22 we can hardly refuse it now."
The files include a squeak of complaint from her husband, Denis Thatcher.
"Another dreaded State Banquet I am afraid," the diary secretary wrote to him. He responded that he had planned on dinner with fellow rugby fans, but would skip it for the banquet.
"What I do for the Party!" he wrote.