29003
The Union , under Lincoln and Secretary of State William H. Seward worked to block this , and threatened war if any country officially recognized the existence of the Confederate States of America .
 Union, Lincoln, William H. Seward, Confederate States of America
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Union, Lincoln, William H. Seward, Confederate States of America