In "A Rose for Emily," Homer is a Northerner, as opposed to a Southerner, and it is very important that he is a Yankee.
The story presents a South that is still recovering and changing following the collapse of the Southern economy during and following the Civil War.
The townspeople represent the new South, the South after the economy that was based on plantations has collapsed.
Emily represents the old South, and she does not adjust well to the new society. Emily's holding on to the past, to the way things were before, is representative of the South holding on to a past that was seen as glorious.
Homer is from the victorious North. He is a Yankee. He is looked down upon by the townspeople, and Emily is criticized when she is seen with him. In the socially conservative South, being seen with a beau in public is anathema, but being seen with a beau from the North is even worse. He is seen as "below" Emily.
The story is a bit of a microcosm of the South after the Civil War, and Homer is part of the invading and unwanted North.