Watch the trailer for 'Lincoln'
Day-Lewis, who originally turned down the role before being persuaded by Spielberg, scored the New York Film Critics Circle award for best actor.
The letter from the star of films including 'There Will Be Blood' and 'The Gangs of New York' thanks the director for considering him, but most definitely declines.
It's thought that Day-Lewis will receive an Oscar nomination for his part in the film, and is likely to be among the favourites to win.
The letter reads:
"It was a real pleasure just to sit and talk with you. I listened very carefully to what you had to say about this compelling history, and I've since read the script and found it in all the detail in which it describes these monumental events and in the compassionate portraits of all the principal characters, both powerful and moving.
"I can't account for how at any given moment I feel the need to explore life as opposed to another, but I do know that I can only do this work if I feel almost as if there is no choice; that a subject coincides inexplicably with a very personal need and a very specific moment in time.
"In this case, as fascinated as I was by Abe, it was the fascination of a grateful spectator who longed to see a story told, rather than that of a participant.
"That's how I feel now in spite of myself, and though I can't be sure that this won't change, I couldn't dream of encouraging you to keep it open on a mere possibility.
"I do hope this makes sense Steven, I'm glad you're making the film, I wish you the strength for it, and I send both my very best wishes and my sincere gratitude to you for having considered me."
'Lincoln' has already received a glut of award nominations so far, including 10 BAFTA nominations -- ironically Day-Lewis is up for best leading actor -- the most of any film this year.
Related Video: 'Lincoln' leads BAFTAs, 'Twilight' leads RAZZIESBen Arnold writes for Yahoo! Movies UK&IE