As I was sorting through the pictures of Marcia I found at the Maryland Historical Society, one of them caught my eye, mainly because it wasn't a picture of Marcia.
It was a picture of her car, which she called "The Grey Lady", and along with the photograph, there was a little card, explaining the car and offering people a ride in it. She also mentions that the car has her monogram on the door!
I was curious about the car, and could get a general date of the time period because the picture was taken in front of 1211 Cathedral Street, which was built in 1909. I estimated the car to be late 1910's or so, but checked with a friend who collects vintage cars. He confirmed the general date, and informed me that this particular car was known as a "doctor's coupe" and that it wasn't a Ford, because at that time, Ford only made black cars. So it was likely a Buick or a Dodge.
Apparently, small cars like this, with two seats and a large trunk, were preferred by physicians who made house calls, and could carry a nurse and a lot of equipment. The coupe had to be dependable in all sorts of weather, day or night, so it was an enclosed car.
Unfortunately, most of the early 1900's Medical Journals are bound, and have had the advertising pages at the beginning and ends of the volumes removed, so I can't check and see if there are adverts for these Doctor's Coupes.
What is interesting is that Marcia, probably in her early 40's at that time, had her own car and was driving herself around the city and environs. She was the Executive Secretary of the Faculty at that time, and probably had a lot of meetings with physicians. They couldn't always be expected to come to her.