Project Workflow

The workflow for this project was roughly divided into three stages.

In the first stage, I compiled data about the estates into a spreadsheet. This both served to make the data easier to work with and let me use it as a layer on ArcGIS to serve as the basis for my map. The bulk of my data came from Long Island’s Prominent North Shore Families: Their Estates and Their Country Homes, a two-volume book by Raymond and Judith Spinzia that had information on the estate owners, construction information, and more. While scraping the data I had to make decisions about what to include and how to deal with unclear data; I explain these decisions in greater detail below.

An example entry from the Spinzias’ book. Image by Elizabeth Carr.

After sorting through the Spinzias’ book, I found coordinates for the estates via two main sources:, and a Wikimapia page of historic homes on Long Island. Since these sites are either crowdsourced or were created by a non-professional, I verified the information I found with what I already knew from the Spinzia’s book. At this point, I also created the more generalized categories for the acreage, years of construction and demolition, industry of the financier, and current use. These categories were not explicitly included in the data but grouping the points made them significantly easier to visualize.

After creating the spreadsheet, I used it to build an ArcGIS map. I manipulated each field to show the data I wanted, as well as uploaded and georeferenced era-appropriate maps that provided context for the data.

Finally, I analyzed the maps and looked for patterns. The results of this analysis can be found on the Findings page. By doing this analysis, I was hoping to answer questions about who built these estates, why they chose to build them, and what their legacy has been.

Data Collection

For the sake of data collection, I made a number of choices about which estates to include and which to exclude. I also made decisions along the way about how to define my criteria, and how to work with the available data.


  • Estate was built between 1890 and 1930
  • Estate was located in Nassau or Suffolk County, NY
  • Estate was located north of, or just south of the Long Island Expressway (I-495), which runs approximately through the midpoint of the island
  • Estate was named

I selected the years based on a general consensus of the “Gold Coast Era” as beginning in the early 1890s and ending at the onset of the Great Depression around 1930. The qualification of the estate being named arose while finding data; there were many houses I found that had very minimal information, including not having a name. I chose to only select named estates based on the belief that if a person had the means to create an estate, they would most likely be giving that property a formal name. Unfortunately this does exclude houses whose names were lost over time, but given the data I had available it seemed to be the best option.

Although I had originally intended to include an acreage criterion, I quickly realized this was problematic due to the unreliability of the data. Many estates were missing their acreage information or only had it for the years 1929, 1932, and 1946; well after their construction. When estates had different acreages listed over time, I used the largest number.

For the scope of this project, I included only the original estate names and owners. Many of these houses passed hands during my time frame, and later owners would remodel, rename, or otherwise “edit” the original estate. I chose to only include this original information because I wanted to focus on the people who had financed the house and made the decisions regarding its location, size, style, etc. In cases where an original name or owner was not known, I used the earliest available name.

There were several cases of houses built prior to my starting date of 1890 that at some point within the time range of 1890-1930 were purchased and significantly remodeled (ex: the architectural style changed, new wings were added, etc.). I have included these estates, since the remodeling that made them into a “Gold Coast Estate” took place during my timeframe, even though the construction of the original structure did not.

I did not include any house with a missing construction year, since there was no way to verify whether the estate was built within the time range of 1890-1930.

If a house was still standing but there was not data on its usage, it was assumed the house was a private residence, since researching it would theoretically return results if it were a business or otherwise being used for non-private purposes. For houses whose precise location I could not determine, I substituted rough coordinates based on the available location information.

In looking at the people who originally built the home, I chose to use the term “financier” as opposed to builder, owner, or resident. This is because I was interested in who had funded the building of the estate, and how they had the financial means to do so. The other terms suggested people who lived in a home and might have owned it, but did not necessarily suggest that they were responsible for its creation. “Financier” as used in relation to the original owner or builder should not be confused with “financier” as referring to people who worked in the finance industry.

When recording the industry for each original estate owner, the goal was to pick the industry they had made their money in, in order to understand how they had the financial means to build their estates. Since the resources I had available often listed many jobs without years that they were held, I chose to record the first job listed, with the assumption that this was either the first one they held and thus where they made their initial money, or it was the most important job they had.

However, I made some exceptions to this rule for people who held multiple significant positions. For example, the first job listed for William Russell Grace Sr. was “director – Marine National Bank.” Grace, however, also served two non-consecutive terms as the Mayor of New York City; thus both positions are listed in his entry.

Ambiguity of data

One difficulty that I and many others looking to do spatial history have encountered is the unreliability of data. Historical data is often riddled with inaccuracies, has been lost to time, or was never recorded in the first place. With location-based research this can be frustrating, since an incorrect recording of a location could dramatically affect the conclusions drawn from that data. This ambiguity is why I made so many decisions about how to handle the data, and I did my best to include accurate information about these homes. However, I would be remiss to not acknowledge that my data might not be 100% accurate, and I welcome feedback that would allow me to correct these inaccuracies.

Next page: Findings