Yet Fifth Avenue, from the day the first houses pushed northward from Washington Square, has had its literary landmarks, figures, and traditions.
Ten years ago, had you been passing of a summer's day a house at the southeast corner of the Avenue and Ninth Street, you might have seen emerging from the front door, a figure clad in white flannel, and looked upon the countenance of the creator of Tom Sawyer and Huckleberry Finn.

It was, and is, a house of red brick, a house of three stories and a high basement, built by the architect who had designed Grace Church.
The number is 21.

Clemens went to live there in the autumn of 1904, remaining for a time at the near-by Grosvenor while the new habitation was being put in order, and the home furniture that had been brought from Hartford was being installed.

When No.

21 was ready for occupation, only Clemens and his daughter Jean went to live there, for Clara had not recovered from the strain of her mother's long illness, and the shock of her death, and was in retirement under the care of a trained nurse.
Clemens, according to his biographer, Albert Bigelow Paine, was lonely in No.