Ellis Island is not a natural island. Originally three small oyster islands (known as "Little Oyster Island" and others), it was artificially expanded using landfill—largely from subway excavation and ballast from ships—between 1892 and 1934. The final 27.5-acre island was created in stages to accommodate the growing immigration complex. Today's island is entirely engineered, a testament to early 20th-century civil engineering and the federal commitment to a centralized immigration gateway.