
Johnson became President upon the assassination of John F. Kennedy in Dallas, Texas on November 22, 1963. Kennedy had proposed a sweeping the civil rights bill in June of 1963 and in late October 1963, Kennedy called the House leaders to the White House to try and firm up the necessary votes for passage. The numbers did not look good. After Kennedy's death, Johnson took the initiative in finishing what Kennedy started and worked to end a filibuster by Southern Democrats in March 1964. As a result, he was able to get the bill out of the house and in the Senate where it was passed. Johnson's bill was even stronger than the one proposed by Kennedy. He signed the revised bill into law on July 2, 1964. As he put down his pen, Johnson told an aide, "We have lost the South for a generation", and his prediction appears to have come true. The next president, Richard Nixon, adopted a Southern Strategy which took votes from the Democrats for the Republican Party.
In 1965, Johnson achieved passage of a second civil rights bill, the Voting Rights Act, which outlawed discrimination in voting, allowing millions of southern African-Americans to vote for the first time. The Voting Rights Act removed barriers African-Americans faced in being allowed to vote. Specifically, it eliminated literacy tests which southerners used to stifle the black vote for years. As a result of the act, the number of black voters increased dramatically. This led to an increase in African American office holders.
After the murder of civil rights worker Viola Liuzzo, Johnson went on television to announce the arrest of four Ku Klux Klansmen implicated in her death. He angrily denounced the Klan as a "hooded society of bigots," and warned them to "return to a decent society before it's too late." Johnson was the first President to arrest and prosecute members of the Klan since Ulysses S. Grant almost a century earlier. He sought support for his push for civil rights, encouraging support from churches North and South.
In a speech he gave as part of the Howard University commencement address on June 4, 1965, Johnson said that both the government and the nation needed to help achieve the following goals:
...to shatter forever not only the barriers of law and public practice, but the walls which bound the condition of many by the color of his skin. To dissolve, as best we can, the antique enmities of the heart which diminish the holder, divide the great democracy, and do wrong — great wrong — to the children of God.
In 1967, Johnson nominated civil rights attorney Thurgood Marshall to be the first African American Associate Justice of the Supreme Court. To head the new Department of Housing and Urban Development, Johnson appointed Robert C. Weaver as the first African-American cabinet secretary in any U.S. presidential administration.
Author Lisa Jardine wrote the following excellent summary of LBJ's presidency in a 2009 article for The Independent:
Johnson had politically defined himself as someone who could make a difference to the lives of those unable to speak up for themselves – the poor, the discriminated against, the old. The mounting tide of anger against him, the increasingly large and disorderly demonstrations, wrecked his confidence, leaving him a broken man. On 31 March 1968, he unexpectedly withdrew from the nomination process for the presidency, leaving the contest to Robert Kennedy and Eugene McCarthy. Three days later, Ho Chi Minh announced that North Vietnam was ready to enter into peace talks (although the war would in fact go on for a further seven years).
Johnson remained in office for 10 more months, a lame-duck President, watching helplessly as social unrest increased right across the United States. On 4 April, Martin Luther King Jr. was assassinated. Two months later, so was Robert Kennedy. In August, police clashed with anti-war demonstrators at the Democratic National Convention in Chicago. In November, the Republican Richard Nixon was elected President.
The tirelessly active Lyndon B Johnson retired to his ranch and a life of idleness, self-pity and isolation. He let himself go – taking up smoking and drinking again, although he knew his heart-condition made both inadvisable. On 22 January 1973, at the age of 64, he suffered his third heart attack, which this time was fatal. Had he run for another term in 1968 and won; that would have been almost exactly the date at which he would have finally left office. Five days later, the Vietnam War ended in a peace treaty, signed in Paris, between America and North Vietnam.
Lyndon B Johnson's reputation today, such as it is, rests upon a number of classic biographies written between 1976 and 1998. Their final assessments of the 36th President of the United States, arrived at as the 20th century was drawing to a close, fall somewhere between apology and regret: apology for Johnson's disastrous involvement of America in a war in South-east Asia that it could not win, with the accompanying enormous loss of life; and regret that the fine ambitions and domestic legislative triumphs of the early years of his presidency gave way to the disillusion and disappointment that led up to his decision not to run again in 1968...
Today our assessment is likely to be somewhat different – less hesitant and more admiring. Johnson was a consummate politician, perfectly attuned to the ways of Capitol Hill, who understood the complex systems underpinning the United States Congress, and how to exploit its rules to achieve clear political goals. His finest work was done behind the scenes and out of sight, in the halls and corridors of the Senate, cajoling and threatening by turns to sway opinions and win crucial votes. The realisation that those tactics were of no conceivable use in foreign policy, especially in South-east Asia, ultimately utterly undermined Johnson's confidence in his own leadership.
Yet his record of getting domestic legislation into statute to help the socially disadvantaged remains impressive. In 1965, building on Roosevelt's social security legislation of the Thirties, Johnson added Medicare – health insurance for those aged 65 and over. His "Great Society" programme produced large amounts of federal funding for public schools, as well as money for urban renewal, crime prevention, and widespread measures to fight poverty. All of which laid the groundwork for socially responsible legislation whose impact can still be felt in the United States today. They were enormously popular at the time they were put in place, and continue to deserve general recognition today as effective and forward-looking measures.

The message we end up taking away from the Johnson presidency is that, while we may rest our hopes on the idealistic presidents, in the end it is the deft political operators, the people who can really deal with Washington in all its complexity, who make policy of lasting importance. In the legislation Johnson undertook to introduce, he based the tactics for achieving his goal on a shrewd assessment of the opposition, key arguments to be countered and won, carefully calculated sums concerning voting numbers and previous voting patterns. When necessary he did not hesitate to amend draft legislation to appease one or more groups of opponents, nor to make promises concerning future legislation, which could be seen as compromising his intended outcomes. Those strategies have earned him the admiration of many political scientists, but send a shudder through the ranks of those who like their heroes to be more idealistic and single-minded.