Short answers, pulled from the story.
The Campaign for Nuclear Disarmament was launched at a public gathering on the 17th of February 1958 at Central Hall, Westminster. Five thousand people attended this first event and a few hundred demonstrated outside Downing Street afterward.
Gerald Holtom designed the symbol in 1958 which combined semaphore signals for N and D within a circle. Holtom later described the figure as representing an individual in despair with hands outstretched.
Membership reached 460,000 under Joan Ruddock's chairmanship from 1981 to 1985 according to CND claims. The BBC reported 110,000 members in 1985 and 32,000 in 2006.
The British security service MI5 carried out surveillance of Campaign for Nuclear Disarmament members considered subversive from the late 1960s until the mid-1970s. During this period MI5 designated CND as communist-controlled due to its being communist-penetrated.
The Labour Party voted at its 1960 Conference for unilateral nuclear disarmament representing CND's greatest influence. This coincided with the highest level of public support for its programme before Labour lost the 1959 election.