Men began to call on the name of the LORD.
The LORD in capital letters is what our Bible translations put instead of YHVH in the Hebrew. Some pronounce His name Yahweh, some Jehovah or Yehovah. Our God has a name and He wants us to call to Him.
Consider some of these verses:
Psalm 120:1 "I call on YHVH in my distress." and 124:8 says: "Our help is in the name of YHVH." and 141:1 - "O YHVH - I call to you, come quickly."
Isaiah 42:8 "I am YHVH, that is my name." and 12:4 says "Give thanks to YHVH call on His name, YHWH Almighty is His name of renown."
Joel 2:32 says "Everyone who calls on the name of YHVH will be saved."
YHVH God wants to dwell with His creation. He is a relational Creator who did not make us to be alone or go our own way. It is very hard to relate to someone without knowing their name. YHVH knows we need Him so He tells us His name so we might call to Him and know Him and be near to Him.