Step 1: Understanding the historical context.
The "Law Assembly" here refers to the Law Commission formed during British India to codify laws for the Indian administration.
Step 2: Identifying the first Chairman.
The First Law Commission was established in 1834 under the Charter Act of 1833, and Lord Thomas Babington Macaulay was appointed as its first Chairman.
Step 3: Significance of Lord Macaulay's role.
Lord Macaulay played a pivotal role in drafting the Indian Penal Code (IPC), which continues to form the backbone of criminal law in India today.