Which type of rig was first used in the United States for oil well drilling?

• A. Rotary drill rig
• B. Air percussion rig
• C. Cable-tool rig
• D. Steam-powered rig

Answer: (C)

The key idea here is understanding how oil-well drilling started in the United States. Early American wells were drilled with a cable-tool rig, a percussion method that uses a heavy drill bit attached to a cable. The bit is repeatedly lifted and slammed down to crush the rock, and the cuttings are removed with a bailer rather than pumped out. This approach was the standard method when the first wells were drilled in the mid-1800s and remained dominant for many decades.

Why this fits best: it represents the earliest drilling technology used in the U.S. for oil, before the industry shifted to rotary drilling and other modern methods. Rotary rigs, air percussion, and steam-powered rigs came later or in different contexts, so they weren’t the first. The cable-tool method laid the foundational technique that made the early oil era possible.