Some “trolley” lines did indeed haul freight. Many used what they called “freight motors” that looked like the larger passenger interurbans with trolley-like ends with a boxcar middle.
Some operations, like the Texas Electric here in Texas, also had “trailers” that looked like unpowered freight motors.
Yes, some “trolley” lines did haul “steam road” freight cars, at least on their own lines and away from streetcar tracks. The Pacific Electric and the Sacramento Northern have already been mentioned. The Texas Electric hauled freight cars on parts of its own trackage; so did the Connecticut Company. These were handled by middle-cab low-voltage (600 v) DC electric locomotives.
i think one or two freight trolley lines might survive in Iowa.
