What A Marriage Date Might Tell Us About Abolitionists?

     On April 12, 1859 David F. Baylor and Annetta Rebecca Mannen were married in McLean County, Illinois.  The marriage was blessed with two children: son, Cory Oscar and daughter, Isabelle Maria (Marie Isabell on death certificate).  Isabelle was born on Nov. 25, 1862.  It is unlikely that Isabelle remembered her mother because Annetta passed away on April 27, 1864  when Isabelle was less than two years old.  
     But why did the young couple choose April 12, 1859 as a wedding date?

     A census record might shed a little light on the reason.  An 1859 Kansas Census shows that Rebecca's parents arrived in Lykins County, Kansas in May, 1859.  So it would seem that the date of the marriage was chosen as a result of her parents plan to leave Illinois.  But why the rush?

Ancestry.com.. Kansas State Census Collection, 1855-1925.
Provo, UT, USA: Ancestry.com Operations Inc, 2009.

     In the late 1850s Kansas was a battleground between pro- and anti-slavery forces.  Many abolitionists came from other states to live in the area and ensure Kansas' entry as a free or anti-slavery state.  The Mannens settled on a farm about 8 miles from where John Brown, famed abolitionist, lived. Lykins County had been named after a Baptist missionary, Dr. David Lykins.  Lykins County was renamed as Miami county in 1861 because of the pro-slavery views of Dr. Lykins.  

     Did Rebecca's parents, William R. and Mariah Mannen go to Kansas to help the anti-slavery forces?  Rebecca's brother fought with the Union Army but other than that I haven't found any other clues.