Captain John Smith of England first explored the shores of MD in 1608. He published an authoritative map in 1612. http://smithtrail.net/captain-john-smith/smiths-maps/
In 1634, King Charles I of England granted George Calvert, Lord Baltimore rights to the area now known as Maryland. http://www.mdhs.org/education/teachers/md-history-qa
Prior to that time the area now known as Clifton Park is believed to have been a general use hunting and foraging area. Holcomb, Eric L., The City as Suburb: A History of Northeast Baltimore since 1660, ©2005 Center for American Places, p. 4-5
The British ironworks company, Principio, took control of much of the area. Established locally in 1715, they extracted iron ore for Britain. Ownership came under dispute in 1776. The formal transfer was completed in 1780. Journal, Volume 4, By United States Association of Charcoal Iron Workers, page 348 (Google Books)
In 1801, Henry Thompson purchased what is now Clifton Park. After the death of Henry Thompson in 1828, the property was sold to a local businessman. The deal fell through. The property was sold to Johns Hopkins in 1838. http://explore.baltimoreheritage.org/items/show/22#.VduQR_ZViko
Johns Hopkins used the property as his summer estate. After his death in 1863, the property was transferred to Johns Hopkins University. http://www.olmstedmaryland.org/wp-content/uploads/2012/07/FMOPL_CliftonPark.pdf, p 2
The University used the grounds primarily for athletics. They sold the property to the City of Baltimore in 1894. http://mht.maryland.gov/nr/NRDetail.aspx?FROM=NRHDCountyList.aspx&NRID=1522&propertyName=Clifton%20Park&mapLocation=nrb1522.jpg&COUNTY=Baltimore%20City
Clifton Park is a complex park. It falls under the jurisdiction of Baltimore City Departments of Recreation and Parks, Public Schools, and Public Works. Civic Works and the Municipal Golf Course Association have long term leases. St. Vincent De Paul cemetery is entirely contained within the grounds of Clifton Park. The CSX railroad traverse the park, as well.