I learned recently that the records for the 1940 US Census will be available online next month. They aren't indexed by name yet, so researchers need census enumeration district numbers to perform searches. (Ancestry.com will complete a name index later.) I found the census map showing local districts for Sugar Land at the US Census Web site.
I identified what I needed for my family. The Kellys lived in district 79-11. The Rachuigs in 79-13. The map shows the lay of the land in 1940 to a reasonably good degree although structures are sketchy. (A legend for structures must exist somewhere.)
For some reason I thought about Santa Anna's sweep through Fort Bend County in 1836 as I reviewed the map. I read Wharton's History of Fort Bend County a couple of years ago and learned the route he took. Wharton's account is less than clear in spots because contemporaneous accounts are contradictory, but it cleared up some fundamental mistakes I grew up with.
First, Thompson's Ferry (where Santa Anna crossed the Brazos) was west of Richmond as I've denoted on the map -- not down by present-day Thompson. Second, Santa Anna never crossed Oyster Creek. He stayed north of Oyster Creek when he left Richmond and headed toward Stafford's Point. Third, Santa Anna split his army into multiple groups. (In fact, he left some troops in Richmond.) Strictly speaking, his army took several routes eastward from San Antonio to San Jacinto.
Here's the 1940 Census map with annotations.
Here's a Google map with roughly the same annotated path. I wanted to overlay the two maps, but I couldn't get it to work well. The annotations aren't exactly identical, but they're relatively close.
