Abolition and gay marriage

Four years ago, I wondered on this blog whether 18th-century abolition causes 21st-century gay marriage. Or, to put it less mystifyingly, and more precisely, I wondered if the order in which states abolished slavery in the late eighteenth and early nineteenth centuries would predict the order in which they instituted gay marriages or civil unions in the late twentieth and early twenty-first. At the time, I only had two data points, Vermont and Massachusetts, but I predicted that New Hampshire would legalize gay unions before New York would, preconceptions about the isle of Manhattan notwithstanding. Today the New Hampshire legislature passed a bill authorizing same-sex unions, which the governor is expected to sign.

Not that I’m the sort to say I told you so or anything. Nonetheless, in triumph, I thought I’d revisit my data. Four years ago I came up with my 18th/19th-century list by ranking the states according to the proportions of slaves to total population reported in the 1790 census. That was laziness on my part; I did it because I didn’t have at hand a list of the years each state abolished slavery. I’m still lazy, but today such a list is readily available, so here’s a comparison based on slightly better 19th-century data and a few more years of 21st-century data: side-by-side tables of states in the order they instituted gay marriage or civil unions (through a court ruling or legislation) and in the order abolished slavery (through a constitutional provision, legislation, or a court ruling):

Advent of gay marriage or civil unions

1999 Vermont
2004 Massachusetts
2005 Connecticut
2006 New Jersey
2007 New Hampshire

Abolition of slavery

1777 Vermont
1780 Pennsylvania
1783 Massachusetts
1783 New Hampshire
1784 Rhode Island
1784 Connecticut
1799 New York
1802 Ohio
1804 New Jersey
1816 Indiana
1818 Illinois

Sources: Human Rights Campaign and Leon F. Litwack, North of Slavery: The Negro in the Free States, 1790-1860, qtd. by Afrolumens Project’s FAQ about slavery in Pennsylvania

As you can see, I went the extra mile and colorized the state names to make it easier to see the pattern. Maybe it’s just a coincidence, but I think it’s a pretty striking one. I would have thought that by now the pattern would have been broken by the passage of gay-union laws in states like California, low in the right column not because they abolished slavery later but because they didn’t exist until later. But though California has come close, it hasn’t passed gay civil-union laws yet.

My new prediction, then: gay marriage in Pennsylvania, which looks overdue.