chicagoSvg = function(geoJsonFeaturesCollection) {
const height = 1.3 * width;
const projection = d3.geoTransverseMercator()
.rotate([88 + 20 / 60, -36 - 40 / 60])
.fitSize([width, height], geoJsonFeaturesCollection);
const pathGenerator = d3.geoPath()
.projection(projection);
const svg = d3.create('svg')
.attr("viewBox", [0, 0, width, height]);
const g = svg.append('g')
.selectAll('path')
.data(geoJsonFeaturesCollection.features)
.enter()
.append('path')
.attr('d', pathGenerator)
.attr('fill', d => 'lightSkyBlue');
return svg.node();
}