Answer by taking a quote from the following article:

Abbey Road is the eleventh album by English rock band the Beatles, released on 26 September 1969 by Apple Records. The recording sessions for the album were the last in which all four Beatles participated. Although Let It Be was the final album that the Beatles completed before the band's dissolution in April 1970, most of the album had been recorded before the Abbey Road sessions began. A double A-side single from the album, "Something"/"Come

The front cover design, a photograph of the group on a zebra crossing, was based on ideas sketched by McCartney, and taken on 8 August 1969 outside EMI Studios in Abbey Road. At 11:35 that morning, photographer Iain Macmillan was given only ten minutes to take the photo whilst he stood on a step-ladder and a policeman held up traffic behind the camera. Macmillan took six photographs, which McCartney later examined with a magnifying glass before deciding which of the shots would be used upon the album sleeve.  In the image selected by McCartney, the group walk across the street in single file from left to right, with Lennon leading, followed by Starr, McCartney, and Harrison. McCartney is barefoot and out of step with the other members. Apart from Harrison, the group are wearing suits designed by Tommy Nutter. To the left of the picture, parked next to the zebra crossing, is a white Volkswagen Beetle which belonged to one of the people living in the block of flats across from the recording studio. After the album was released, the number plate (LMW 281F) was stolen repeatedly from the car. In 1986, the car was sold at auction for PS2,530 and in 2001 was on display in a museum in Germany. The man standing on the pavement to the right of the picture is Paul Cole (7 July 1911 - 13 February 2008), an American tourist unaware he had been photographed until he saw the album cover months later. On the original cover, McCartney holds a cigarette; in 2003 several US poster companies airbrushed this cigarette out of the image, without permission from either Apple or McCartney.  Shortly after the album's release the cover became part of the "Paul is dead" rumour that was spreading across college campuses in the United States. According to followers of the rumour, the cover depicted the Beatles walking out of a cemetery in a funeral procession. The procession was led by Lennon, dressed in white, as a religious figure, Starr, dressed in black, as the undertaker, McCartney, out of step with the others, as a barefoot corpse and Harrison, dressed in denim, as the gravedigger. The left-handed McCartney is holding a cigarette in his right hand, said to indicate an imposter and the license plate on the Volkswagen parked on the street is 28IF, meaning McCartney would have been 28 if he had lived.

what happened when they did that
Shortly after the album's release the cover became part of the "Paul is dead" rumour that was spreading across college campuses