sentences:  In 1861 the British garrison was withdrawn from Western Australia, and so that year an Act of Parliament was passed authorising the creation of a corps of volunteers.Around this time, the colony's military forces totalled about 700 men serving in foot and mounted infantry units, organised into the Western Australian Volunteer Force which was raised primarily in Perth, Fremantle and Pinjarra.By 1862 the force consisted of units such as the Perth Volunteer Rifles, the Fremantle Volunteer Rifles and the Pinjarra Mounted Volunteers.