Writer Alan Bennett returned to his Yorkshire roots on Wednesday to support protests against the Menwith Hill US surveillance base near Harrogate.
Alan Bennett will speak at the Independence From America event
The protesters, who also included comedian Mark Steel, are opposed to US military bases on British soil.
There has been a demonstration outside the base every 4 July - America's Independence Day - for 20 years.
The Campaign for the Accountability of American Bases (CAAB) said: "We will not be silenced."
Veteran campaigner Lindis Percy said: "Menwith Hill epitomises all that is wrong in the unhealthy, dependent and moribund relationship between the US and UK governments.
"Menwith Hill is crucial to the crazy and dangerous American missile defence programme, it is key to the illegal war in Iraq and key to the mess of Afghanistan.
"Change is well overdue."
There was one arrest for a public order offence, said the police.