Visualizing Birth Evidence

So, prompted by some work I've been doing on trying to figure out birth, marriage, and death dates for a number of my husband's Chicago relatives, I've come up with a way to visually compare the evidence. It isn't a ground breaking approach--I'm sure a lot of you do something similar--but it's pretty simple and I'm finding it really helpful so I thought I'd share.

First of all, in the three years that I've been working on learning to "do it right," I've fallen into a routine of gathering evidence into a table to help me wrap my mind around it. Each line includes a year for sorting purposes, a citation, the information, and quick notation to help me consider the quality of the source, the information, and the evidence. The table is for my own use and it looks something like this:

Birth Date Evidence for Frank M. Smith

0	Source	Information	Source O/D/A	Info P/S/I	Evidence D/I/N
1850	1850 U. S. census, Cook County, Illinois, population schedule, Chicago, First Ward, n.p., dwelling 275, family 293, F (male) Smith; digital image, FamilySearch (https://www.familysearch.org : accessed 7 May 2018), citing NARA microfilm publication M432, roll 102.	Age 13 [born 2 Jun 1836 to 1 Jun 1837]	O	I	D
1860	1860 U. S. census, Cook County, Illinois, population schedule, Chicago, First Ward, p. 36 (penned), dwelling [illegible], family [illegible], Jas A. Smith; digital image, FamilySearch(https://www.familysearch.org/ark:/61903/1:1:MXH7-C5Q : accessed 7 May 2018), citing NARA microfilm publication M653, roll 164	Age 23 [born 2 Jun 1836 to 1 Jun 1837]	O	I	D
1885	Cook County, Illinois, probate file no. 4-2790 (1885), Marcia M. Smith, proof of heirship, 2 July 1885; Cook County Circuit Court Archives, Chicago.	Informant, Frank M. Smith stated that he was forty eight years on 2 July 1885. [born 3 July 1836 to 2 July 1837]	D	S	D
1888	"Chicago, Illinois, Voter Registration, 1888," database with images, Ancestry (https://search.ancestry.com/search/db.aspx?dbid=5991 : accessed 5 November 2018), entry for Frank M. Smith born in Illinois.	Applied 16 Oct 1888; had been in precinct, county, and state for 52 years [born 17 Oct 1835 to 16 Oct 1836]	D?	S	I
1894	American Ancestry: Giving the Name and Descent, in the Male Line, of Americans Whose Ancestors Settled in the United States Previous to the Declaration of Independence, A. D. 1776, Vol. IX (Albany, N.Y.: Joel Munsell’s Sons, 1894), 132; digital image, Google Books (https://books.google.com/books?id=7Ew7AQAAIAAJ : accessed 5 November 2018).	"Francis Marion Smith, born in Chicago, Sep 27, 1836"	A	I	D
1899	Rosehill Cemetery Office (Chicago, Illinois), burial record, int. no. 48981, Francis Smith.	Age 63; died 13 October 1899 [born 14 Oct 1835 to 13 Oct 1836]	D	I	D
1899	"Chicago death certificates, 1878-1915," FamilySearch(https://www.familysearch.org/search/catalog/42925) > 1033071 > image 1265, Chicago death certificate no. 18070 (13 October 1899), Francis M. Smith.	Age 63; died 13 October 1899 [born 14 Oct 1835 to 13 Oct 1836]	O	I	D
1899	"Frank Smith Passes Away," The Chicago Tribune, 14 October 1899, p. 7, col. 1; digital image, Newspapers.com (https://www.newspapers.com/image/349269502/ : accessed 9 April 2018).	Born in Chicago in 1836.	O	I	D

But, as you can see, even though the evidence is neatly summarized in one place, it's still hard to grasp what's what.

Here's where a visual summary like the one below comes in.

1835												1836												1837
1	2	3	4	5	6	7	8	9	10	11	12	1	2	3	4	5	6	7	8	9	10	11	12	1	2	3	4	5	6	7	8	9	10	11	12
																		Proof of Heirship
									Death Certificate
									Burial Record
												Obituary
																	1850 Census
																	1860 Census
									1888 Voter Registration
																					Published Family History

Basically, it's a table that allows me to plot dates or calculated date ranges from the sources listed in the evidence table. It took a bit of tweaking to set up the template, but now that I have it, it's pretty quick and easy to fill it in. Sometimes I use color, but this one happens to be grayscale.

In this case, it shows, at a glance, that the exact date published in the family history falls into the ranges suggested by information from every other source collected to date. It also shows, by way of the shading, which sources should be the most reliable. Frank was the informant for his age on the proof of heirship record and for his length of residence on the voter registration record (which should have been his age because he was born in Chicago) so I've colored those squares darker than the records that have unknown informants.

Here's another example:

Birth date Evidence for Charles B. Smith

1827												1828												1829												1830
1	2	3	4	5	6	7	8	9	10	11	12	1	2	3	4	5	6	7	8	9	10	11	12	1	2	3	4	5	6	7	8	9	10	11	12	1	2	3	4	5	6	7	8	9	10	11	12
																	1850 Census
																	1860 Census
					1870 Census
																													1880 Census
																		Proof of Heirship
																																		Death Certificate
																																		Burial Record
																																		Obituary
												Parents’ Marriage												Parents’ Marriage
																																							Brother Born
																						Possible Birth

The parents probably married in 1828, but one source suggests 1829 and it can't be completely ruled out, thus the two entries in yellow/orange. The brother's birth month and year, shown in green, is very likely correct. His death at sixteen months was recorded in a church register and reported in a local newspaper. 

Knowing these two things, it's easy to see that the birth date range suggested by the age in the 1870 census is an outlier that doesn't work well with the parents' probable marriage year.  And, the birth dates and date ranges suggested by the 1880 census and the death-related records aren't feasible. I'm quite sure the two children were born to the same mother and it's very unlikely she gave birth to one child five months after another.

But, if the exact birth date provided in the obituary is off by a year--the hypothesized date is indicated in blue--then it would be consistent with his age provided by a brother in the proof of heirship document and with his age as recorded in two census records. 

It would be necessary, of course, to examine specific evidence in detail, in writing, before drawing any conclusions, but the visual makes it easy to see a path that a proof argument might take.

I'm curious to know how the rest of you approach this topic. If you can offer further advice for sorting through birth, marriage, and/or death date evidence, please post a comment. Thanks!