The movement started as a response to the Rowlatt Act, which allowed the British government to detain individuals without trial. It then gained momentum and evolved into a broader campaign demanding Swaraj (self-rule) and protesting against various oppressive policies implemented by the British Raj.
While the movement had its roots in Ahmedabad, Gujarat, where Gandhiji organized Satyagraha against the mill workers' plight, it soon spread across India, with major centers of activity in various cities and villages.
Therefore, it's more accurate to say the Savinay Avagya Andolan was a national movement rather than being confined to a specific location.