For men who weren’t regular soldiers [or reservists] one of the largest group of soldiers to serve in South Africa during the Boer War were those who volunteered to serve in the Imperial Yeomanry.
Most were already members of locally raised County Yeomanry Cavalry Regiments that were only intended for home defence not service abroad. To overcome this an Act was passed creating the Imperial Yeomanry for service in South Africa.
The reason I mention it is on Kevin Asplin’s site at http://hometown.aol.co.uk/kevinasplin/home.html
he lists all members of the I.Y. and there are 2 Hainsworth’s listed:
Hainsworth, James Michael, 802, Private,10th Coy., 3rd Bn. I.Y and
Hainsworth, Lionel, 1973, Private, 11th Coy., 3rd Bn. I.Y.
The 3rd Battalion I.Y. was sponsored by Yorkshire & Notinghamshire Yeomanry Cavalry regiments. The 10th Company 3rd Bn was raised in 1900 and sponsored by the Nottinghamshire Regiment of Yeomanry Cavalry (Sherwood Rangers) and the 11th Company by the Queen's Own Yorkshire Dragoons.
It was common for men to volunteer for nearby I.Y. units if their own was over subscribed. May be worth noting the names for future reference – you never know.