1870 Census - Madigans in Manhattan

This may be the 1870 census of the Madigan family. They were still living in Manhattan, and the census on the page prior says that it is enumerating Canal St., between Greenwich and Watt. This is an area of downtown Manhattan right around the entrance to the Holland Tunnel. We've been told that Mary Ann Madigan Mulcahy was born on Lake St. in Manhattan, but I've never been able to find evidence that there is or ever was a Lake St. in Manhattan, so I won't take that as the gospel truth just yet. This record shows what appears to be "Mat" and "Mary" Madigan and their daughter Mary, age 2. I know, I know, it doesn't sound like the right family - but could "Margaret" have been abbreviated "Marg" in handwriting where a "y" and a "g" are nearly indistinguishable? Yes, I'm taking a big leap there, and I know it, and I'm not relying on that information in any way, nor do I suggest that you do. However, having looked over a few of the other pages in this census, it seems that this census taker did make a habit of abbreviating "Margaret" as "Marg." Usually, yes, it was more clear than it is here, but hey, this is the penultimate page of the district. I'm sure he was tired. Also, this "Mat Madigan" is listed as a "carman," and really - how many carmen named Mat Madigan could have possibly been running around New York at one time? Remember that I say this knowing full well that our Julia and Patrick Mulvaney shared Brooklyn with another couple named Julia and Patrick Mulvaney at the very same time, and that Suffern once had a William O'Hara with a son named Kevin O'Hara in an entirely separate family than ours - coincidences do happen. Still, I present this on the possibility that it might be our Madigan family, and we'll see if we can find proof - though what that would entail, I'm not sure. I'll know it when I see it, I guess.

(interesting note, since I paged to the next and last image, that of the last page of the census for this enumeration district, where the census taker tallies the total number of inhabitants: 1246 inhabitants, of whom only a single 1 is non-white (a "colored male"). Imagine that!)