On August 22nd, 1776 British troops landed on Long Island after having been driven from Boston mere months ago. They had been floating along the the coastlines during the summer. Washington had skirmishers go and attack their boats (Hamilton and the HMS Asia affair) while he entrenched his troops around York City/Manhattan Island and the surrounding works of Brooklyn Heights.
By now, readers familiar with the first few pages of Patriots know that Tallmadge and the Connecticut men have already joined and had been waiting around, passing the time with rudimentary training of troops. Most of the officers who will form the 2nd Light participated in either the Battle of Long Island, the retreat to Brooklyn Heights, the evacuation to Manhattan Island or the full retreat to Harlem Heights and then to White Plains. The notable exception is Ezekiel Belden who was recorded as being posted with part of his regiment at Fort Washington. He would later barely escape with his life as Fort Washington & Lee eventually fell to the British advance in September and October.
What's notable is the Marylanders that stayed behind covering the troops' evacuation and retreat from Jamaica Pass and the Gowanus Creek (near modern day JFK airport). There's a really nice supplemental book I read during my research that I highly recommend for those interested in the 250 Marylanders that sacrificed themselves to cover the retreat. [Washington's Immortals - by Patrick K. O'Donnell (2016, Grove Press NY)]
I'll post a bit more on August 29th, the date that troops evacuated Brooklyn Heights to Manhattan under the cover of heavy fog and rain. (And also my thoughts re: Tallmadge going back for his horse of all things.)