I asked the question, When were the sketches done for the birdseye map of L.A. which was copyrighted in 1909?--anticipating that it would have been a year or two before.
By chance, I ran across a starting point, the C.C. Chapman Building at the northeast corner of Wall and 5th, breaking ground on or about Valentine's Day 1909:
LA Times, 2/14/1909
Well, golly, it's on the birdseye map:
So, should it ever make a difference:
The 1909 birdseye map was very up to date!