|Polk's 1920 City Directory, Indianapolis, Indiana|
Pierpont Clarence M mach h1150 Spruce
Pierpont Cora F clk CCC&StLRy r1150 S Spruce
Pierpont Edw L lab h1722 W Minnesota
Pierpont Esther A (wid Jno T) h1742 W Morris
Pierpont Ezra uphlr h1537 Draper
Pierpont Frank H mach r1742 W Morris
Pierpont Gilbert engr h2113 W Morris
Pierpont Wm E elect r967 King av
Pierpont Wm R fnshr h2812 Schofield av
The unidentified Clarence and Cora Pierpont remain at the same address they lived in the 1919 directory. Their relationship to the other Pierponts hasn't been established.
The Edward L. Pierpont is believed to be the son of John T. and Hester Pierpont, and younger brother of Harry's father, Joseph Gilbert.
The Esther A. Pierpont is the same as Hester Pierpont, Harry's grandmother, and widow of John T. Pierpont. In 1919 directory, John T. was alive at the same address.
The Ezra Pierpont is believed to be another son of John T. and Hester Pierpont, and brother of Joseph Gilbert, Harry's father.
The Frank H. Pierpont is another son of John T. and Hester Pierpont, the younger brother of Harry's father. In the 1919 directory, he was listed as being in the U.S. Army.
The Gilbert Pierpont listed as an engineer is Harry's father, Joseph Gilbert Pierpont. There is a gap between his appearance in 1920 Indianapolis, but not in the city after 1912, the last city directory that listed him.
The remaining Pierponts, William E. and William R., remain unidentified, though they appear in the 1919 directory at the same address.