Merwin, Sam. The House of Many Worlds
Divergence: c 1801 CE
Summary: Time guardians intervene in affairs in divergent worlds, including one in which Aaron Burr conquered and reshaped the USA.
Published: Doubleday 1951; Galaxy SF Novel 12 (1952); Modern Literary Editions 1967 (012307049?); Ace 1982 (0441344461BUY).
— Revision of "The House of Many Worlds", in Startling Stories, September 1951.

Merwin, Sam. "Three Faces of Time"
Summary: Cross and vertical time-travel adventure in a slightly different ancient Rome.
Comments: Not to be confused with Frank Belknap Long's novel of the same name.
Published: In Ace Double #D-121 (Ace 1955).
— Revision of "Journey to Misenum", in Startling Stories, August 1953.