Here's a scan of an old postcard from my collection, addressed to Miss Clara Petersen in Edgar Nebraska. The postmark is July 12, 1913. Feel free to take the image to use in your own artwork!
To copy the image, click on it, then, when it loads full size, right-click and choose "Save As" from the menu. Give it a cool name (like "Fantastic clip art from Karen" --ha!) and save it. It's 200 dpi at full-size, so it will print out well.