Why are people from Sunderland called "mackems"?

Solution 1:

The Wikipedia entry has sourced its answer from the Oxford English Dictionary entry for 'mackem'. As far as word origins are considered, probably as authentic as it gets.

EDIT: As it seems that everyone cannot access the OED link, here's an excerpt. There are two possible origins attributed:

Probably with allusion to the phrase mack 'em and tack 'em and variations thereof, freq. said to refer to the shipbuilding industry of the region

or..

Perhaps partly also with allusion to the pronunciation of make typical of Wearside, as contrasted with that of Tyneside.

Solution 2:

As Sunderland was once known for shipbuilding there was only 2 main forms of employment...shipbuilding by day and stealing from the ships they'd helped build by night. Apparently there was a saying "they mak'em then tak'em" meaning they build (the ships) then steal from them. The mak'em bit stuck and so we are now known as 'makems' or so they say!!?

Solution 3:

My uncle was from Sunderland and was clear that it was a reference to the difference in accent which differentiated a Tynesider from a Wearsider. Geordies would say "maek" and "taek", Wearsiders "mak" and "tak". Nothing to do with shipbuilding. There was probably more shipbuilding on the Tyne than the Wear.

I should add that my uncle and my parents were born in the 1920s and knew this usage from childhood. It's not a recent coinage.