For 18 years, a chunk of land at Interstate 90 and East Riverside Boulevard has waited to deliver a hospital. The city and MercyRockford Health System on Thursday ended tough negotiations with an agreement for the city to annex 263 acres owned by MercyRockford Health System. That agreement, if approved by the City Council, will green light development of a $485 million medical campus that could accelerate growth in the city's northeast quadrant.