legislation_cosponsors: 113-hconres-8, U000031

Cosponsors for tracked legislation. Distinguishes original cosponsors (signed on at introduction) from later additions. Linked to congress_members via bioguide_id.

This data as json

bill_id	bioguide_id	full_name	party	state	sponsorship_date	is_original_cosponsor
113-hconres-8	U000031	Rep. Upton, Fred [R-MI-6]	R	MI	2013-01-15	1