Swaggies were blokes who carried their swag, walking from property to property (called homesteads or ranches in the US but more usually called "stations" in Oz), looking for work and, sometimes, looking to avoid working too hard for the obligatory handout of basic tucker. The process was sometimes called the tucker track. There was a technique of rolling one's clobber into a blanket that could be carried comfortably over the shoulder. The nearest north American equivalent was a hobo but I'm not sure they carried swags, let alone waltzed matilda.

Cheers, Rowan