My greatgrandfather was Johan Carl Meiwald (and various other spellings of the name including Maywald) was born in Prussia and came to the US in the mid 1850's. He was born in 1827. He migrated to the German community in Benton County, MO when he arrived.
I have not found his passage but your Gus having come from Galveston gives me a clue. I just need to find the manifests of the Galveston arrivals from Germany.