Charlie Chaplin
United Artists, Mildred Harris, and The Kid

After the release of Shoulder Arms, Chaplin requested more money from First National, which was refused. Frustrated with their lack of concern for quality, and worried about rumours of a possible merger between the company and Famous Players–Lasky, Chaplin joined forces with Douglas Fairbanks, Mary Pickford and D. W. Griffith to form a new distribution company, United Artists, in January 1919. The arrangement was revolutionary in the film industry, as it enabled the four partners – all creative artists – to personally fund their pictures and have complete control. Chaplin was eager to start with the new company and offered to buy out his contract with First National. They refused and insisted that he complete the final six films owed.

Before the creation of United Artists, Chaplin married for the first time. The 16-year-old actress Mildred Harris had revealed that she was pregnant with his child, and in September 1918, he married her quietly in Los Angeles to avoid controversy. Soon after, the pregnancy was found to be false. Chaplin was unhappy with the union and, feeling that marriage stunted his creativity, struggled over the production of his film Sunnyside. Harris was by then legitimately pregnant, and on 7 July 1919, gave birth to a son. Norman Spencer Chaplin was born malformed and died three days later. The marriage ended in April 1920, with Chaplin explaining in his autobiography that they were "irreconcilably mismated".

Losing the child, plus his own childhood experiences, are thought to have influenced Chaplin's next film, which turned the Tramp into the caretaker of a young boy. For this new venture, Chaplin also wished to do more than comedy and, according to Louvish, "make his mark on a changed world". Filming on The Kid began in August 1919, with four-year-old Jackie Coogan his co-star. The Kid was in production for nine months until May 1920 and, at 68 minutes, it was Chaplin's longest picture to date. Dealing with issues of poverty and parent–child separation, The Kid was one of the earliest films to combine comedy and drama. It was released in January 1921 with instant success, and, by 1924, had been screened in over 50 countries.

Chaplin spent five months on his next film, the two-reeler The Idle Class. Work on the picture was for a time delayed by more turmoil in his personal life. First National had on 12 April announced Chaplin's engagement to the actress May Collins, whom he had hired to be his secretary at the studio. By early June, however, Chaplin "suddenly decided he could scarcely stand to be in the same room" as Collins, but instead of breaking off the engagement directly, he "stopped coming in to work, sending word that he was suffering from a bad case of influenza, which May knew to be a lie."

Ultimately work on the film resumed, and following its September 1921 release, Chaplin chose to return to England for the first time in almost a decade. He wrote a book about his journey, titled My Wonderful Visit. He then worked to fulfil his First National contract, releasing Pay Day in February 1922. The Pilgrim, his final short film, was delayed by distribution disagreements with the studio and released a year later.
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