Many genealogy sites are rushing to get these records on line as fast as possible. Ancestry.com already has all the states up on it's site for free until April 10th. You can also find them here:
Use the tools at the bottom and put in the cross streets. If you know where they lived in Lowell you should be able to narrow it down to one enumeration district. Keep a window open with google maps to help you out. Remember that some street names have changed. University Avenue used to be Moody Street in 1940.
It is a great resource for researching your WW1 ancestor. My husband's grandfather, Irving Loucraft, a Sergeant in the 101st Infantry served with distinction in France during WW1. He survived the war and was the holder of the Purple Heart with 2 clusters and the Silver Star. Here he is in the 1940 Census in Lowell on Walker Street with his family.
|1940 Census Image - Walker Street Lowell, MA|
Irving Loucraft and family