Isn't all politics?
And it was (is) 3/4 rather than 2/3 to ratify.
# State Date *  
1 Illinois Feb 1, 1865  
2 Rhode Island Feb 2, 1865  
3 Michigan Feb 3, 1865  
4 Maryland Feb 3, 1865  
5 New York Feb 3, 1865  
6 Pennsylvania Feb 3, 1865  
7 West Virginia Feb 3, 1865  
8 Missouri Feb 6, 1865  
9 Maine Feb 7, 1865  
10 Kansas Feb 7, 1865  
11 Massachusetts Feb 7, 1865  
12 Virginia Feb 9, 1865  
13 Ohio Feb 10, 1865  
14 Indiana Feb 13, 1865  
15 Nevada Feb 16, 1865  
16 Louisiana Feb 17, 1865  
17 Minnesota Feb 23, 1865  
18 Wisconsin Feb 24, 1865  
19 Vermont Mar 8, 1865  
20 Tennessee Apr 7, 1865  
21 Arkansas Apr 14, 1865  
22 Connecticut May 4, 1865  
23 New Hampshire Jul 1, 1865  
24 South Carolina Nov 13, 1865  
25 Alabama Dec 2, 1865  
26 North Carolina Dec 4, 1865  
27 Georgia Dec 6, 1865 * 
28 Oregon Dec 8, 1865  
29 California Dec 19, 1865  
30 Florida Dec 28, 1865  
31 Iowa Jan 15, 1866  
32 New Jersey Jan 23, 1866  
33 Texas Feb 18, 1870  
34 Delaware Feb 12, 1901  
35 Kentucky Mar 18, 1976  
36 Mississippi Mar 16, 1995 *  
Ratified in 309 days 
* Mississippi ratified the amendment in 1995, but because the state never officially notified the US Archivist, the ratification is not official.
This amendment was specifically rejected by Delaware on Feb 8, 1865; by Kentucky on Feb 24, 1865; by New Jersey on Mar 16, 1865; and by Mississippi on Dec 4, 1865.