I am 95% certain I've identified a Schwenningen connection for the following Rochester, NY JAUCH/YAUCH family:
From the 1850 Census:
Jacob JAUCH, 48 (b. abt. 1802) with wife Agnes, 46 (b. abt. 1804) and the following children:
Eliza JAUCH, 21 (b. abt. 1829)
Jacob JAUCH, 16 (b. abt. 1834)
Agnes JAUCH, 10 (b. abt. 1840)
John JAUCH, 7 (b. abt. 1843) [May be the John YAUCH also in Rochester in the 1880 census.]
Martin JAUCH, 5 (b. abt. 1845)
Conrad JAUCH, 8 mos. (therefore b. Jan/Feb 1850)
Reference: 1850 US Census; Rochester, Monroe County, NY; 6th ward; p. 589 (handwritten); p. 295 (stamped); image 141 on ancestry.com.
NOTE: This family is still in Rochester in the 1880 census, but spelled YAUCH. Jacob, a sign painter, is 78; Agnes his wife is still alive at 74. Living with them is daughter Agnes married to George FISCHER, milliner, age 42, and two sons Irving Fischer (8) and George W Fischer (17). See Film 1254864, T9-0864, 335A.
UPDATE: I'm 95% certain that this is the family found in the Schwenningen church records here:
http://worldconnect.rootsweb.com/cgi-bin/igm.cgi?op=GET&....
If so, and if the data collected so far is accurate, we have this line back to Michael & Katharina Jauch, and her father Hanss Jauch back to abt. 1600.
-- Jillaine Smith
http://freepages.genealogy.rootsweb.com/~jillaine/jauch