By 'brick walls' here, I mean more recent genealogical questions that do not have enough descendants to warrant investigations by the professional genealogist writers.
Basil Maxwell -
Ignatius Wheeler -
Matilda Townsend - Probably daughter of George Washington Townsend Sr and Mary Combs, who were originally living in Bracken co KY before moving to Christian co KY and then Brown co IL. Link is not proven, as GW Townsend's probate record is sparse. Search needs to be made in Adams co IL probate (which is not online) to see if Matilda received anything from her possible father's estate after 1844.
George Clifton -
Sarah Nagle -
Isaac Thomson - I have seen trees state that he is a son of Moses Thomson and Margaret (Hendershot?) but this is an unconfirmed link. Union Co IN probate is only viewable in person.
Elizabeth Shurts -
Mary Seeley - The Seeley Society claims, without a source, that she is a daughter of Abel Seeley and Sarah Guire, but there is no other genealogical work I have seen that gives her parentage. They simply state that she married George Batterson. There are several Seeley families that could be her parents, so Abel and Sarah would need to eliminated or confirmed first, through the probate, which can only be viewed in person in CT.
Amos Kelley - In many trees he is shown to be a son of Amos Kelley and Elizabeth Jackson, but there is another completely different man with that name living next to the widow Elizabeth Jackson Kelley in the 1850 Census.
Julia Ann Alvis - Is supposed to be a daughter of James Alvis and Lucy (Ingraham?), whose connection to the rest of the Alvis line is unknown, which seems quite likely, but I have not proven the link.
Abraham Elliott and William Elliott - I have not see the proof that links Abraham Elliott to William Elliott
Emaline Cunningham - Most trees that she is in do not contain guesses as to her parentage, but those that do state she is a daughter of Silas Cunningham, which seems likely due to her and her husband having a son with that unusual name, and living next to Silas Cunningham in one of the censuses. This link would have to be documented better before I am willing to add it to my tree.
Abraham P. Burns - Seems to appear out of nowhere in Delaware Co IN in 1848 to marry his wife, Sarah Ann Pendroy.
Mary Wiseman - Poor/no sourced trees
Manuel Maria Gonzalez and Mariana Coz - This couple is supposed to have lived in Veracruz at one point, but there are also some baptisms in Mexico City that seem to be them; searches in Veracruz's baptismal records did not yield any for his son (also named Manuel). I believe Manuel is a Spanish immigrant but this is not proven. There are very few 'Coz' baptisms in Mexico to know where to begin there, either.
James W. Stephens and Jesus Gifford -